A different style "insurance " is at your local Racor dealer.
They have a kit that installs between the tank top overflow and the over
flow fitting that sticks thru the hull side.
Yes, but.... I got a couple of those and had to return them. They only
work if mounted with a particular orientation and vent hose path. The
place I returned them to said they get a lot returned. The way my boat was
built, there wasn't enough height between the top of the tanks and the
bottom of the decks to fit everything in the specified orientation. Life
would be simpler if the vents were above the deck level and then this
wouldn't be a problem in the first place.
Anyhow, my cheap and reliable solution has just been to sit in the door of
the engine room with a flashlight watching the sight glass while the boat
is fueled. When the glass tops off (about 20 seconds afterwards actually)
I tell my wife to stop pumping and we've never spilled a drop this way. It
does make it a two person operation though.
Bill Martin
m/v Telegraph Hill
http://home.earthlink.net/~martinwj/