We use the deet wipes readily available at REI on our ankles and feet before heading to shore in the evenings.

One tip....especially for the person whose child get bug bites overnight....he is likely bringing them into bed with him and then they feast. We ALWAYS dip our feet/legs up to about our knee into the water before stepping onto the boat from the dingy. no-see-ums wash off and you dont bring any aboard.