We had the original Windscoop Ventilator on board our previous boat which does a decent job, but when the wind shifts directions, you have to go up top and reposition the scoop accordingly. This wouldn't be an issue for a shallow drafted boat that points into the wind at anchor, but heavy boats like ours that draw 6' + don't always point into the wind and move with the current instead.
|The Original Windscoop|
There are several 3- or 4-way or "omni directional" wind scoops on the market, but the most common designs are narrower at top than at hatch level, which in our opinion loses a lot of air.
|Plastimo's Omni-Directional Wind Scoop|
And with "custom" hatch measurements, most commercial wind scoops wouldn't work with our hatch dimensions. So after looking at many designs on the market, we set out to design our own.
We wanted to maximize airflow as much as possible, so with the bowsprit and high free board, we needed a particularly tall scoop. We also wanted a rigid top that would keep its shape and withstand reasonable wind gusts. And we needed strong, yet light weight material that would move easily, along with a "skirt" that would help direct the airflow and keep the leeward scoop pieces neatly in place.
The result: a 6 1/2 foot tall scoop with four panels made from rip stop nylon. Each panel is wider at the top and tapers down to match the width of the hatch opening. The top is made of nylon flag material, which has better UV characteristics than regular rip stop. A fiberglassed piece of Luann is sandwiched between two pieces of the green nylon flag material to give the top some rigidity, and the 4 panels are sewn to the 4 sides of the top. We bound the four panel edges together with 3/8" Sunbrella binding tape, and attached tube webbing loops to all of the top and bottom to serve as attachment points. The "skirt" was made of Phifertex, which keeps the side panels in place without blocking too much air flow. (The first skirt was made of Sunbrella, but it really knocked down the air and was quickly replaced).
This design really drives the air down below -- you can feel the breeze coming out the cockpit and even flowing into the aft cabin! And whenever the wind changes, the wind scoop self adjusts, giving us one less thing to mess with!