Larry wrote:

The fuel tank needs more than just a vent hose, too. It needs some kind
of floating ball water trap that will seal if water tries to come into
the fuel vent in an event like this. Got one? Ever seen one? As the
air must go INTO the tank, we can't just put a flapper valve in it. It
has to be a floating ball that's normally open but closes the hole when
liquid floods the trap. Wish we had one on Lionheart. Let me know if
you've seen something like this. My coffee pot is a Cuisinart with a
vacuum bottle carafe, not a heater/glass pot. The most ingenious coffee
pot engineers design Cuisinarts. The screw-on cap on this pot has a
series of little gravity and floating balls that ingeniously prevent heat
from escaping the pot, while automatically opening the holes at the
appropriate time to let new coffee pour into the top and coffee pour out
the spout ONLY when the pot is tilted towards the spout. The rest of the
time it's sealed. This kind of technology needs to be in everyone's fuel
vent. It's not...it's a hose that assumes the boat never tilts over 20
degrees...dammit.

Pretty common on commercial ships:

http://www.wagerusa.com/pages/marine/1500vertical.html

http://www.wagerusa.com/pages/marine/1700series.html

Evan Gatehouse