Boric Acid.
Kills bugs without poisoning the boat.
The product's name is Roach-Pruf.

Capt. Frank

Keith wrote:

I've never had a roach problem on a boat before, but have got one now. Those
damm little German cockroaches have gotten a foothold, and nothing I'm using
is doing much good. I have used those Raid Max smoke type foggers twice,
sprayed everywhere with Raid Max, and then used the "wet" foggers. I can
knock them down for awhile, but not out.

Raid Max used to be the best, lasted for months. They've reformulated it to
a water-based formulation that smells completely differently from the old
style, and it doesn't seem to do anything unless you spray it right on them,
despite their claims that it "kills for up to 6 months".

Any ideas?