Airvents (anti siphon valves) and yachts: how do they work and how do they protect your boat? 

Just love the way that the bucket of water is balanced on a battery!

Thanks! Just a suggestion -- clear buckets and colored fluid would make this much clearer.

excellent video and very useful information, thanks.

Excellent video!

Very good video. Thank you!

Is it okay to remove the internal part of the valve on the legacy product similar to the demonstration here with the newer valve? The vent tube runs to a small through hull above the water line, so no worries about filing the bilge.