Originally posted by Apple:

they wont attack you unless you basically beach your boat. you can still sail around the shallows

So Deathsquitos wont attack you Huh? You must have had a unique experience to the rest of us.

OP if you have full Iron fully upgraded and or a good shield and food you should be able to fight off a a couple of the Bugs of Death if you sail too close to their shore, But you don't go slow look for them and pick them off with your Bow.

If you don't trust your Bowman-ship then its time to go around that area