I hear a lot of "closed cell" here in the forum but what is it anyway? If it is really closed cell, then how does the air get in to inflate the kite? If you can get air in somehow, does that mean water can get in as well when you fly them on water?

This might be a stupid question but not seen in person, I really don't understand how it works........ - Brian

Open cell foil, the usual Ram air that we all fly and love.

Closed cell foil, The Peter Lynn's and Flysurfer sort of stuff, still a twin skin kite, but it's got air vents with some sort of one way baffle, so the air goes in the vent to inflate the kite and give it the shape, but the baffles prevent the air from gettting back out, so even when the kite's sitting on the ground, it'll stay fully inflated. Because the kite stay's full of air, there's no room for water to get inside the kite once it's full, water relaunchable so they can be used for surf safely.

Some like the Flysurfer are fully bridaled like your open cell kites, the PL's are rigged up more like a surf kite(LEI)