If I'm not careful I get the "gas puking vent" when I fill up and judging from this OSO search, so do others.

http://www.offshoreonly.com/forums/s...gas+tank+vents


So my next question is why do boats have separate vents from the filler? Cars have the vent tapped into the top of the filler neck so the pump will shut off when it tries to puke. What's wrong with that setup and then use a vented cap like older cars?

probly something to do with the size of the tank.... mine does the same thing I know someone told me Formula has a check valve you can put on the vent hose to prevent the Pukeing, last time I filled up mine wayyyy to much and it leaked dripped out for two days....

Not sure why the separate vent, but I had a problem with my vents letting in water when it rained - we sealed mine off and then replaced the fuel fills with ones that were an integrated vented unit. They don't look as cool as the old annodized fills, but now I'm not emptying my fuel water separators everytime I go boating after it rains.

Can not help much on the why they are vented the way they are, I just ordered one of these. Should help with spills when filling up.

http://www.iboats.com/mall/index.cgi...&view_id=37945

http://www.boatus.com/Foundation/Fin...s40/vented.htm
deck fills with vents.
There is also a proiduct which i cant find now, but catches the vented fuel.

found it
http://www.shipstore.com/SS/HTML/DAV/DAV376.html

On my Hustler when it pukes it will even start to siphon and start really flowing out