Those cobalt blue “by-the-wind” sailors that recently coated our coastal beaches are Velella velella, free-floating hydrozoans that call the top of the open ocean home. Beginning life in the middle of the Pacific Ocean, its tidy gelatinous jelly fish body is outfitted with a diagonal opaque white sail that growsat a specific angle. The angle is dependent on geography: on our western side of the Pacific the sails are angled northeast to southwest but is reversed in other waters—each form sending them in opposite directions. Their voyages across seas are at the whims of winds and currents. Along their travels they consume a very locally available diet of prey and fish that live and can be caught just below the surface of the water through their mouths that are set in the midst of the underside of their bodies.
Shifts in winds and spring currents occasionally bring them to our and other shores along the West Coast of North America starting in British Columbia then moving south over several weeks time. Once beached, their color fades and they die and disintegrate.