I am repeating this in my 356 thread tracker forum so It does not get lost. It is the same info as I put into the general Interest Big Boats forum. I installed a large Nicro solar vent on the forward hatch of my 356, and replaced the scoop on the cabin roof with another Micro solar vent. Installatiuon on the roof is a no brainer as it just plugs into the original hole. Installation on the hatch was easy and no problem--just put masking tape down on the hatch before you saw to eliminate scratches. The hatch is so thick Lexan that it appears about as strong as before, and I consider all the warnings about weakening the hatch so much red herring. Just don't jump on it. I can walk on it with no problem. I use both vents in the intake mode and crack the hatch over the aft berth for exhaust. The through-ventilation is excellent. Another tip: While I had the big canvas boat cover on for the winter there was little light reaching the vents, not enough to charge the batteries let alone turn the fans. Simple solution was to put 50 W desktop halogen lighting fixtures ($15 at Home Depot) on the deck and shine them onto the vents. Great solution--they ran 24 hrs per day even with the boat cover on. Ivan