Stop Sailing because even if you Kill it more will come and then comes an Alpha Leed and kiss your little raft goodbye. You couls try and motorboat they last a little longer LOL
motorboat, dony stop on the middle of the ocean tho. they can be destroy by the whale, but they are faster thant the whale, so if you keep moving on open waters you'll be ok.
Put a plat x on the back of your boat have it set to wild only and asleep as soon as you hear the whale or get hit turn that plant on and head to the closest shore, other strat is to have a box full of rafts as he attacks you drop a raft behind you and head to shore