A modular marine vessel has a variable
hull and a plurality of boat forming modules including a bow section module, a load section module having a bow end and an aft end, and a bulkhead forming module is detachably connected to each bow and aft end of the load section module. The bulkhead forming module that is connected at the bow end of the load section module is detachably connected to the bow section module. Each boat forming and bulkhead forming module includes a topside section and a
hull bottom side section. The topside section of each boat forming module has a shell gunnel portion, and the
hull bottom side section of each boat forming module has a pivotally mounted bottom shell hull portion. The gunnel and hull portions of the load and bow section modules are detachably connected end-to-end, and sealingly juxtaposed the detachably connected bulkhead forming module to prevent water from entering the boat when the boat engages water. The bottom shell hull portion is pivotally mounted across a
keel tunnel using a pneumatic, hydraulic, mechanical, or electro-mechanical
actuator to form a preselected hull shape as desired. Novel mechanisms for sealing module connections, for module attachment, for pivoting hull panels, for hull pivot drives, and energy conversion systems for the marine vessel of the invention are disclosed.