Looks fine if everyone agrees. Although, looking at wikipedia, keelboats may be too big for these guys. I'll have to wait until tonight to look up the D&D definition of a keelboat, though.
Habitat/Society: Sea wyrms lair in underwater caves or in remote caves on islands. They can breathe equally well in air or water and move about on land by slithering like a snake. They eat just about anything but are particularly fond of fish and fruit. They have been known to slither around a fruit tree and constrict it in an attempt to get at fruit which is beyond their normal reach.