They’re not for use underway, but hood-shaped fabric air scoops can be a godsend when there’s but a slight breeze stirring the heat.

There’s no secret to their effectiveness. They’re just big. They grab a lot of breeze and build it into a bit of wind to funnel belowdecks.

Sailmakers have been known to cut and stitch custom versions of these devices. However, there are apparently only four “ready-mades” on the market. …