Ideas to get more air down the hatch
A. Some hatches act as vents, but can leak in very bad seas. Small drips drop between the coamings and out the drains. These also let air in. B. Extra dorade vents can be added to the sides, and V-shaped props (C) dropped in the gaps, will hold the lid up at an angle.
D. This hatch has a window to let in light and show there are security bars to deter break-in.
E. Making it as a complete box and then sawing the lid off ensures a good fit. F. Hinges can be made with removable pins, so it will open fore or aft. Lift-off, or piano hinges have also been used. Catches should be able to be opened from above and below. G. But a strongback gives more security, and a nut wheel will save banging your head on a wing nut! H. Pop-up tents with bug screens can be rigged at any angle to keep rain out, or force air in.
I. These bars stop the sheets snagging the vent or hatch, and can be rigged with a rain cover.
J. Black bug nets also reduce light levels and give some privacy from other crews crossing the deck. K. A quick sun/privacy fix, on a charter boat say, is to stow the dinghy like this.
Whether forehatches should hinge fore or aft is a matter for debate, but windsails or windscoops will help force air through them. There are many types... L. This one has a vent to relieve pressure in a gust. M. And some sailors copy the old sailing ship practice of having tall vents, that can be left on at sea. The blue bit is waterproof and secured to the hatch with a bolt-rope and tape.