Lewmar Hatch Vents

[Coops2]

Has anybody had experience good/bad with lewmar hatch vents? If I leave my Lewmar medium profile hatches open even a crack when raining I get water into the cabins. The Lewmar website says their hatch vents are waterproof but I would like some independent confirmation before I go cutting big holes in the middle of my hatches. I suspect I would have them closed while at sea and only unscrewed when on anchor but if anyone can vouch for their ability to let air in and keep water out while underway or at rest I would be pleased to hear of it.

[Orion Jim]

Is it not possible to add a dorade box with a cowl vent? They are eminently seaworthy and provide air circulation regardless of sea state. I have a Marinco solar vent and a Vetus mushroom vent. Both leak if not secured before heading offshore.

[tkeithlu]

Aside from whether or not the Lewmar vents leak, a question I cannot begin to answer, looking at the catalog drawings made me wonder whether they move as much air as you may need. Hot muggy smelly mildewy forward cabins are way down on my preference list. A honkin' big funnel and a dorade box sounds much more like it.