A fiber and a process for obtaining same from a high-modulus polyethylene, extrudable in state-of-the-art equipment and in the absence of previous solubilization in any kind of organic solvent is described, the process comprising providing such a polyethylene, introducing it in a state-of-the-art extruder, extruding it according to a temperature pattern, obtaining an extrudate that is directed to a cooling bath to have its temperature reduced, then directing the extrudate to a first stretcher where it is stretched or drawn into a fiber of improved tenacity, at a first velocity v1, then heating the fiber at nearly 90° C. and then directing said fiber to a second stretcher to be drawn at a final velocity v2, wherein v1<v2, at a draw ratio of 2 / 1 until 65 / 1. The tenacity of the polyethylene fiber obtained by the said process attains at least 4 gf / den, which makes it useful to naval and offshore applications.