-Its rough to say; but if you are at raft - level tech, you have no business anywhere near Plains or the high seas. Skeeters can outrun a Karve too, but I *think* you can outdistance them in a Longship under full sail.-

Deathsquitos are easily dealt with by any bow and any arrow, but they are very much instant death to anything short of Iron/Silver armor and Mountains-equivalent food.

*edit* ahh I see. Its definitely a rough corpse run. I pretty much always make a portal to any new island. You can also always make a decent sized outpost and a bed each time you land somehwere, too.