I'm not a very good navigator because I kept missing the barrels, but I guess I'm lucky when it comes to avoiding whirlpools. I tried @Champpeace's trick and I, too, lived forever :D
I love the title and it gives a mysterious feel of why you are in this endless ocean. Perhaps some dialogue can add story to the game . Like your ship is cursed to sail the oceans forever and instead of just scoring by avoiding whirlpools, you can also score the player by how long they can stay afloat :D