Ultrasonic biofouling prevention system for marine propellers and shafts

Abstract

This invention provides a novel system for preventing marine biofouling on vessel propellers and shafts using a shaft-mounted ultrasonic transducer collar. The system generates ultrasonic energy parallel to the propeller shaft, ensuring uniform and efficient energy distribution for effective biofouling prevention. The collar integrates multiple high-power ultrasonic transducers, each equipped with an internal circuit board for individual control and communication via power cables through a slip ring. The slip ring facilitates the transfer of power without impeding the shaft's rotation. The system employs various ultrasonic waveforms, including continuous, pulsed, and frequency-modulated waves, to maximize energy throughput and adaptability. This innovative configuration reduces maintenance needs, enhances vessel efficiency, and provides a robust, environmentally friendly solution for marine biofouling prevention.

Description

[0001] Ultrasonic Biofouling Prevention System for Marine Propellers and Shafts

[0002] TECHNICAL FIELD

[0003] This invention relates to marine biofouling prevention systems, specifically to a shaft-mounted ultrasonic transducer device designed to protect marine vessel propellers and shafts by generating longitudinal parallel ultrasonic waveforms to prevent the growth of marine organisms.

[0004] BACKGROUND OF THE INVENTION

[0005] Marine biofouling on vessel propellers and shafts is a significant problem that reduces operational efficiency, increases fuel consumption, and escalates maintenance costs. The accumulation of marine organisms on propellers disrupts the hydrodynamic flow, leading to increased drag and reduced propulsion efficiency. Hydrodynamic flow refers to the movement of water around the propeller and shaft, which is essential for optimal propulsion and manoeuvrability.

[0006] Traditional methods to prevent biofouling typically involve the perpendicular mounting of ultrasonic transducers on the stern tube bearing collar. This approach relies on the weight of the stationary propeller shaft to transfer ultrasonic energy, which is typically ineffective. Existing systems also face limitations in energy distribution, leading to uneven biofouling prevention.

[0007] Prior art solutions, such as those involving ultrasonic transducers mounted around the hull or in other non-integral positions, fail to provide consistent biofouling prevention on the propeller and shaft. Additionally, some methods combine ultrasonic waves with other treatments like ozone, which can introduce complexity and additional maintenance requirements.

[0008] There is a need for a more effective solution that ensures consistent biofouling prevention across the entire propeller and shaft, even when the vessel is operating. This new approach should overcome the limitations of traditional methods by providing uniform energy distribution and effective biofouling prevention, thus maintaining optimal hydrodynamic flow and propulsion efficiency.

[0009] SUMMARY OF THE INVENTION

[0010] The present invention provides a marine biofouling prevention system for submerged structures, particularly designed for the propeller shafts of marine vessels. This system introduces a novel arrangement of ultrasonic transducers mounted directly onto the shaft, with each transducer aligned to emit ultrasonic waves parallel to the shaft's longitudinal axis. This parallel configuration enables significantly improved energy transmission, optimized biofouling prevention, and enhanced environmental and operational performance.

[0011] A key benefit of the system is its ability to transmit ultrasonic energy along the length of the propeller shaft, effectively disrupting the attachment and growth of marine organisms. By driving ultrasonic waves parallel to the shaft, the system reduces energy loss typically caused by scattering and absorption, resulting in more efficient energy propagation through the submerged surfaces. This enhanced transmission ensures broader and more consistent biofouling prevention, maintaining vessel propulsion efficiency and minimizing the need for manual cleaning or chemical antifouling agents.

[0012] One of the most significant advantages of this invention is its positive environmental impact. Marine biofouling, when left unchecked, increases drag on vessels, leading to higher fuel consumption and greater energy loads. By preventing biofouling build-up on the propeller, the system helps maintain optimal hydrodynamic performance, reducing fuel consumption and, consequently, lowering CO2 emissions. This improvement directly supports global efforts to reduce the carbon footprint of maritime operations, contributing to cleaner, more sustainable shipping practices.

[0013] In addition to reducing fuel consumption, the system offers long-term operational efficiency by eliminating the need for frequent maintenance interventions such as physical cleaning or chemical treatments. The system operates preventing biofouling growth in real time. This ensures that the vessel maintains optimal performance over extended periods, further reducing operational costs associated with biofouling removal and downtime.

[0014] The system also features real-time frequency modulation and calibration mechanisms that automatically adjust the ultrasonic output based on environmental factors such as water temperature and the degree of biofouling present. This ensures the system continuously operates at peak efficiency, adapting to changing conditions and delivering consistent biofouling prevention.

[0015] By minimizing reliance on toxic chemical antifouling agents, the present system offers an eco- friendly alternative that aligns with increasing environmental regulations for the maritime industry. The reduction in chemical use, combined with the system's ability to lower fuel consumption and CO2 emissions, makes it a highly sustainable solution for long-term biofouling prevention.

[0016] In summary, the present invention represents a major advancement in marine biofouling prevention technology, offering a highly efficient, low-maintenance, and environmentally friendly solution. By maintaining vessel performance, reducing fuel consumption, and lowering emissions, this system provides both economic and environmental benefits, making it an ideal choice for modern, eco- conscious maritime operations.

[0017] The benefits of this invention include:

[0018] 1. Uniform Energy Distribution: Ensures even distribution of ultrasonic energy along the propeller shaft, providing comprehensive biofouling prevention without requiring excessive power.

[0019] 2. Enhanced Energy Transfer: The parallel-to-shaft configuration maximizes the effective transfer of ultrasonic energy along the shaft and propeller, reducing energy losses and ensuring broad coverage.

[0020] 3. Optimized Vessel Efficiency: By preventing biofouling buildup, the system maintains optimal hydrodynamic flow, reducing fuel consumption and supporting lower CO2 emissions, which contributes to more environmentally sustainable operations.

[0021] 4. Reduced Operational Costs: Consistent biofouling prevention significantly lowers the need for frequent maintenance or cleaning, translating into reduced operational downtime and lower overall costs.

[0022] 5. Environmentally Friendly: The system eliminates the need for chemical antifouling agents, providing a cleaner, eco-friendly solution that aligns with global regulations for reduced environmental impact in marine operations. This invention addresses the shortcomings of traditional biofouling prevention methods and prior art by providing a robust, efficient, and environmentally friendly solution for marine vessels.

[0023] Brief Description of the Drawings

[0024] Figure 1: Side view of the ultrasonic transducer collar mounted on a propeller shaft, showing the collar clamped onto the shaft with integrated ultrasonic transducers and the slip ring.

[0025] Figure 2: Isometric view of the ultrasonic transducer collar mounted on a propeller shaft, showing the collar clamped onto the shaft with integrated ultrasonic transducers and the slip ring.

[0026] Figure 3: Detailed view of an individual ultrasonic transducer, highlighting its internal circuit board and components.

[0027] Figure 4: Block diagram of the control and synchronization system, showing the central control system, slip ring, ultrasonic transducers with internal circuit boards, and the synchronization mechanism.

[0028] Detailed Description of Embodiments

[0029] Experimental Verification of Ultrasonic Energy Transmission (with Figures 5, 6, and 7)

[0030] To support the claims regarding the superior energy transmission of ultrasonic waves when driven parallel to a structure's axis, a series of tests were performed, with results documented in Figures 5, 6, and 7. These tests compare the energy transmission for both parallel and perpendicular orientations of the transducers and provide empirical evidence to substantiate the system's configuration for biofouling prevention.

[0031] 1. Experimental Setup:

[0032] As shown in Figure 5, a 1-meter long, 50mm diameter steel rod was used for the experiment. The transducers were bonded to the rod using epoxied mounting footprints and torqued to 20 ft-lbs. Frequency sweeps from 25 kHz to 62.5 kHz were conducted to evaluate ultrasonic energy transmission.

[0033] • Transducer 1 (Channel 1 in Figure 6) drives the ultrasonic waves parallel to the rod axis.

[0034] • Transducer 2 (Channel 2 in Figure 7) drives the waves perpendicular to the rod axis.

[0035] • Transducer 3 (Channel 3 in Figures 6 and 7) measured the received energy in perpendicular orientation at the far end of the rod.

[0036] • Transducer 4 (Channel 4 in Figures 6 and 7) measured the received energy in parallel orientation at the far end of the rod.

[0037] 2. Results:

[0038] Two test conditions were performed:

[0039] 1. Driving energy parallel to the rod axis (Transducer 1 in Figure 5, and Channel 1, Figure 6): o Far-end parallel transducer (Transducer 4, Figure 5, Channel 4, Figure 6) received 22

[0040] V RMS. o Far-end perpendicular transducer (Transducer 3, Figure 5, Channel 3, Figure 6) received 9 V RMS.

[0041] 2. Driving energy perpendicular to the rod axis (Transducer 2, Figure 5, Channel 2, Figure 7): o Far-end parallel transducer (Transducer 4, Figure 5, Channel 4, Figure 7) received 8

[0042] V RMS. o Far-end perpendicular transducer (Transducer 3, Figure 5, Channel 3, Figure 7) received 9 V RMS.

[0043] 3. Analysis:

[0044] • Parallel Driving Orientation:

[0045] When the ultrasonic energy was driven parallel to the rod's axis (Transducer 1), the far-end parallel transducer (Transducer 4) recorded a much higher RMS voltage (22 V, as shown in Figure 6, Channel 4), in contrast, the far-end perpendicular transducer (Transducer 3) at the recorded 9 V. This indicates that more ultrasonic energy travels effectively through the rod when driven in a parallel configuration, resulting in enhanced energy transmission to the receiving transducers.

[0046] • Perpendicular Driving Orientation:

[0047] When the energy was driven perpendicular to the rod's axis (Transducer 2), both far-end parallel and perpendicular transducer recorded significantly lower energy (8V and 9V, respectively, as shown in Figure 7, Channels 3 and 4). This suggests that the perpendicular driving results in more scattering and absorption, leading to greater energy attenuation and reduced efficiency.

[0048] 4. Conclusion:

[0049] The results presented in Figures 5, 6, and 7 demonstrate a clear advantage for driving ultrasonic energy parallel to the axis of a structure. The parallel configuration transmits significantly more energy through the material, supporting the claim that axial alignment enhances energy transmission efficiency. This configuration is critical for more effective biofouling prevention on marine structures.

[0050] These findings validate the invention's design, showing that the parallel transducer configuration provides superior performance compared to the perpendicular arrangement. The increased energy throughput in the parallel configuration ensures more comprehensive biofouling prevention on submerged surfaces.

[0051] Description of the Figures

[0052] Figure 1: Side View of the Ultrasonic Transducer Collar Mounted on a Propeller Shaft

[0053] • Description: This figure provides a side view of the system, showing the collar clamped onto the propeller shaft with the integrated ultrasonic transducers and the slip ring for power and control signal transfer.

[0054] • Elements: o Collar clamped onto the shaft (1) o Propeller shaft (2) o Ultrasonic transducers installed onto the collar (3) o Slip ring (4) o Arrows showing the direction of ultrasonic energy parallel to the shaft towards propeller (5)

[0055] Figure 2: Isometric View of the Ultrasonic Transducer Collar Mounted on a Propeller Shaft

[0056] • Description: This figure provides an isometric view of the system, showing the collar clamped onto the propeller shaft with the integrated ultrasonic transducers and the slip ring for power and control signal transfer.

[0057] • Elements: o Collar clamped onto the shaft (1) o Propeller shaft (2) o Ultrasonic transducers installed onto the collar (3) o Slip ring (4) o Arrows showing the direction of ultrasonic energy parallel to the shaft towards propeller (5)

[0058] Figure 3: Detailed View of an Individual Ultrasonic Transducer

[0059] • Description: This figure shows a detailed view of an individual smart ultrasonic transducer, including its internal circuit board and components.

[0060] • Elements: o Ultrasonic Mounting Pad (6) o Protective sleeve (7) o Internal ultrasonic transducer (8) (indicated but not shown) o Internal circuit board (9) (indicated but not shown)

[0061] Figure 4: Block Diagram of the Control and Synchronization System

[0062] • Description: This block diagram illustrates the control system managing the transducers, including individual control units, synchronization, and calibration mechanisms. It also shows the slip ring for power and signal transfer.

[0063] • Elements: o Central control system (10) o Slip ring for power and signal transfer (4) o Ultrasonic transducers with internal circuit boards (3, 8, 9) o Power and control signal pathways (11)

[0064] Figure 5: Detailed View of Transducer Test Rod

[0065] • Description: This figure depicts the experimental setup, showing the placement of transducers for both parallel and perpendicular tests.

[0066] • Elements: o Driving Transducer parallel to axis (1) o Driving Transducer perpendicular to axis (2) o Receiving Transducer perpendicular to axis, far end (3) o Receiving Transducer Parallel to axis, far end (4)

[0067] Figure 6: Oscilloscope output from Test Rod

[0068] • Description: This figure shows the oscilloscope outputs for the receiving transducers at the far end of the rod when driving Transducer 1 (driving parallel) and receiving with Transducers 3 and 4, channel 3 and channel 4 respectively

[0069] Figure 7: Oscilloscope output from Test Rod

[0070] • Description: This figure shows the oscilloscope outputs for the receiving transducers at the far end of the rod when driving Transducer 2 (driving perpendicular) and receiving with Transducers 3 and 4, channel 3 and channel 4 respectively

[0071] Main Device Description

[0072] The system (Figures 1 and 2) includes a collar (1) clamped onto the propeller shaft (2). The collar houses multiple ultrasonic transducers (3), each equipped with an internal circuit board (9) as shown in Figure 3. The transducers are powered and controlled via a slip ring (4), which allows for electrical contact without impeding the shaft's rotation. The central control system (10) manages the synchronization and calibration of the transducers, as illustrated in Figure 4.

[0073] 1. Overview of the System The system consists of a collar / ring that is clamped onto the propeller shaft, housing multiple high- power ultrasonic transducers. These transducers are connected to a control system via a slip ring that allows for power transfer and communication without impeding the rotation of the shaft.

[0074] 2. Design and Construction

[0075] • Collar Design: o The collar is designed to be clamped directly onto the propeller shaft (2), ensuring a secure and stable connection. It is typically made from a durable material such as billet aluminum to withstand marine conditions. o The collar integrates multiple ultrasonic transducers (3), arranged in a cylindrical configuration around the shaft (2). This arrangement allows the transducers to generate ultrasonic energy parallel to the shaft.

[0076] • Ultrasonic Transducers: o Each transducer contains an internal circuit board (9) that manages its operation and communication. The transducers are capable of generating continuous, pulsed, and frequency-modulated ultrasonic waves. o The transducers are housed inside a protective sleeve (7) that shields the internal components. o The transducers are self-contained units that are synchronized with the rest of the array and communicate control commands from the main control system (10) via the power cables connected through the slip ring (4). o The transducers are mounted monolithic to the collar and are calibrated to operate in unison, creating a unified ultrasonic acoustic energy field.

[0077] 3. Parallel Ultrasonic Energy Generation

[0078] The system generates ultrasonic energy parallel to the propeller shaft. This is achieved by synchronizing the ultrasonic transducers to emit waves in a coordinated manner, ensuring efficient and uniform energy distribution along the shaft and out to the propeller. The system utilizes longitudinal (compression) waves, shear (transverse) waves, and surface (Rayleigh) waves to maximize biofouling prevention.

[0079] • Continuous Waves (CW): o Provide a steady and unbroken ultrasonic energy field, ideal for continuous biofouling prevention. o Ensures a stable level of energy in the propeller shaft, preventing marine organism attachment.

[0080] • Pulsed Waves: o Consist of short bursts of energy followed by intervals of no energy, suitable for disrupting marine growth with intermittent high-energy pulses. o Reduces energy consumption while maintaining effectiveness.

[0081] • Frequency-Modulated Waves: o Vary their frequency over time to prevent marine organisms from adapting to a single frequency. o Covers a broader range of frequencies, making it harder for organisms to resist the ultrasonic energy.

[0082] 4. Control and Synchronization • Slip Ring: o The slip ring (4) allows for the transfer of power and control signals to the transducers without affecting the rotation of the shaft (2). It is isolated from the shaft to prevent electrical interference. o It facilitates the transmission of power to the transducers and enables communication for control commands from the main head unit to each transducer.

[0083] • Control System: o The central control system (10) manages the operation of the transducers, ensuring they are synchronized and calibrated. o Allows for individual control of each transducer (3), optimizing their performance based on real-time conditions. o Regular calibration ensures optimal performance, compensating for variations in the shaft's material properties or environmental conditions.

[0084] 5. Installation and Maintenance

[0085] • Installation: o The collar is machined to fit the specific diameter of the propeller shaft (2) and is clamped securely in place. o The slip ring (4) and control system (10) are installed to handle the electrical connections and synchronization of the transducers.

[0086] • Maintenance: o The system is designed to be low-maintenance, with the ultrasonic energy field preventing biofouling and reducing the need for frequent cleaning. o Regular checks and calibrations ensure the system continues to operate at optimal efficiency.

[0087] 6. Benefits and Advantages

[0088] • Uniform Energy Distribution: o Ensures comprehensive biofouling prevention across the entire propeller and shaft, o Maintains optimal hydrodynamic flow and propulsion efficiency.

[0089] • Enhanced Energy Transfer: o Maximizes the effective transfer of ultrasonic energy parallel to the shaft in the direction of the propeller, improving the impact on biofouling organisms.

[0090] • Improved Efficiency: o Reduces power consumption while maintaining high effectiveness through the use of various waveforms and synchronized smart transducers.

[0091] • Reduced Maintenance: o Lowers operational costs by reducing the frequency of cleaning and maintenance.

[0092] • Environmentally Friendly: o Provides a non-biocide, chemical-free solution to biofouling prevention, contributing to a greener marine environment.

[0093] 7. Detailed Commentary on Graphical Results: Interpretation and Technical Observations

[0094] The results of the tests, as depicted in Figures 6 and 7, show a clear and significant difference between the energy transmission in the parallel and perpendicular orientations of the transducers. These graphical representations provide critical evidence of the unexpected and substantially improved performance achieved by the selective combination of transducer orientations employed in this invention. 7.1. Interpretation of Results in Parallel Orientation (Figure 6):

[0095] When ultrasonic energy was driven parallel to the axis of the rod, Transducer 1 generated longitudinal ultrasonic waves along the rod, which were then detected by Transducer 4 in parallel alignment at the far end. The graphical results in Figure 6 demonstrate that the energy transmission in this configuration reached a peak value of 22 V RMS. This high level of energy transmission is substantially greater than the energy detected by Transducer 3, which is positioned perpendicular to the rod's axis. The perpendicular receiver measured only 9 V RMS, signifying that a substantial portion of the ultrasonic energy was effectively aligned and transmitted along the rod's length in the parallel configuration.

[0096] • Technical Observation: The results reveal an unexpected and highly efficient transmission of ultrasonic energy in the parallel orientation. This demonstrates that when the ultrasonic energy is directed along the rod's axis, the energy propagates with minimal scattering and attenuation, maintaining a high energy throughput. This efficiency is not observed in prior art configurations, where energy is typically driven perpendicular to the axis, leading to significant losses in transmission and a much lower energy reception.

[0097] 7.2. Interpretation of Results in Perpendicular Orientation (Figure 7):

[0098] In contrast, Figure 7 illustrates the results when energy was driven perpendicular to the rod axis by Transducer 2. In this configuration, both the parallel and perpendicular receivers (Transducers 3 and 4) at the far end measured significantly lower energy values, with Transducer 4 (parallel) recording 8 V RMS and Transducer 3 (perpendicular) recording 9 V RMS.

[0099] • Technical Observation: The nearly identical values in both parallel and perpendicular receivers indicate that the perpendicular driving configuration results in considerable energy loss, regardless of the receiver's orientation. This energy attenuation is likely due to increased scattering and absorption as the ultrasonic waves propagate perpendicular to the rod's length, a phenomenon that is markedly absent in the parallel driving configuration.

[0100] 7.3. Comparison and Significance of Results:

[0101] The comparative results from Figures 6 and 7 provide strong empirical support for the superiority of the parallel orientation. The parallel driving configuration not only results in significantly higher energy transmission (as seen with the 22 V RMS peak in Figure 6) but also highlights the shortcomings of the perpendicular driving method, where the energy transfer is largely dissipated.

[0102] • Unexpected Results: It was unexpected that the parallel configuration would exhibit such a pronounced improvement over the perpendicular configuration. This result is highly significant because it challenges the conventional understanding in prior art, where perpendicular driving has been predominantly used. The clear disparity between the energy levels— particularly the nearly threefold increase in the parallel orientation— demonstrates that the selected parallel configuration achieves superior energy transfer, enabling more effective biofouling prevention through enhanced ultrasonic energy propagation.

[0103] 7.4. Special Technical Advantage of Selected Parallel Configuration:

[0104] The selective combination of driving ultrasonic energy parallel to the shaft's axis demonstrates a novel approach that significantly outperforms traditional methods. The results indicate that this configuration maximizes energy efficiency by aligning the ultrasonic waves with the material's structural axis, thus minimizing energy losses that occur through scattering and absorption. This specialized orientation ensures that more energy is directed towards disrupting marine organisms attached to the submerged surfaces, ultimately providing a more robust and efficient biofouling prevention system.

Claims

ClaimsClaim 1: A marine biofouling prevention system for submerged structures, comprising:• a collar configured to be clamped directly onto a propeller shaft of a marine vessel;• a plurality of ultrasonic transducers mounted to the collar; each transducer positioned to generate ultrasonic waves in a direction substantially parallel to the longitudinal axis of the propeller shaft;• a control system configured to drive the ultrasonic transducers with modulated frequencies in a continuous mode, enabling the transmission of ultrasonic energy along the propeller shaft to prevent the attachment of biofouling organisms; wherein the parallel alignment of the transducers with the propeller shaft optimizes energy transmission by minimizing scattering and absorption losses, thereby providing efficient and sustained biofouling prevention over extended operational periods.Claim 2: The system of claim 1, wherein the collar is positioned within a protective housing that shields the ultrasonic transducers from physical damage while allowing efficient transmission of ultrasonic waves into the propeller shaft.Claim 3: The system of claim 1, wherein the control system is configured to generate ultrasonic waves with modulated frequencies, producing continuous guided waves that propagate along the shaft, enhancing the range and uniformity of biofouling prevention and ensuring efficient energy transmission across submerged surfaces.Claim 4: The system of claim 1, wherein the ultrasonic transducers are bonded to the propeller shaft using a high-torque epoxied mounting footprint to ensure stable and efficient energy transfer during marine operation.Claim 5: The system of claim 1, wherein the control system modulates the frequency of the ultrasonic waves to create heterodyned frequencies, thereby expanding the effective frequency range and preventing marine organisms from adapting to a single frequency.Claim 6: The system of claim 5, wherein the frequency modulation creates a combination of waves, increasing the effective reach of ultrasonic energy and providing protection against a broad range of marine biofouling species.Claim 7: The system of claim 1, further comprising a calibration mechanism within the control system, wherein the calibration mechanism adjusts the frequency output of the transducers in real time to optimize performance based on environmental conditions, such as water temperature and fouling severity.Claim 8: The system of claim 1, wherein the ultrasonic waves generated parallel to the propeller shaft reduce energy loss due to scattering and absorption, resulting in a more energy-efficient biofouling prevention system compared to perpendicular wave generation methods.Claim 9: The system of claim 1, wherein the ultrasonic transducers are configured to operate continuously or pulsed operation, ensuring consistent prevention of biofouling over long durations of marine operation.Claim 10: The system of claim 1, wherein the ultrasonic waves propagate through the propeller shaft and into connected submerged structures, providing biofouling prevention not only for the propeller shaft but also for other critical components of the vessel, such as the rudder or hull nearby.Claim 11: A method for preventing marine biofouling on a submerged propeller shaft, comprising: attaching a plurality of ultrasonic transducers to a collar mounted directly onto the propeller shaft; generating ultrasonic waves parallel to the propeller shaft's axis using the transducers; driving the transducers with a control system that continuously modulates the frequency of the ultrasonic waves between as necessary; transmitting the ultrasonic energy along the length of the propeller shaft to prevent biofouling attachment by disrupting the growth and adhesion of marine organisms; wherein the parallel transmission of ultrasonic waves maximizes energy efficiency and minimizes the need for physical cleaning or chemical treatments.Claim 12: The method of claim 11, further comprising the step of modulating the frequency of the ultrasonic waves to generate heterodyned frequencies, broadening the spectrum of frequencies that prevent the attachment of a wider variety of marine species.Claim 13: The method of claim 11, wherein the ultrasonic waves are transmitted continuously throughout the operation of the vessel, providing long-term biofouling prevention without requiring frequent maintenance or manual cleaning.Claim 14: The method of claim 11, wherein the calibration mechanism within the control system automatically adjusts the frequency output to account for varying environmental conditions, optimizing biofouling prevention based on real-time data.Claim 15: The method of claim 11, wherein the ultrasonic waves propagate into connected submerged components of the vessel, providing biofouling prevention for the entire propeller assembly and nearby structures.Claim 16: The system of claim 1, wherein the control system is configured to analyse the calibration values of all available ultrasonic transducers and output the highest calibrated resonant frequency simultaneously across the transducers, generating an ultrasonic shock wave at peak resonance, thereby producing a synchronized frequency sweep for enhanced cleaning of the propeller shaft and

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