I absolutely hate opening the hatches and then, in order to close them back, having to first guess which of the two arms I tightened and then, even having figured that out, having to guess which way the stupid thing twists to loosen.

Well, I saw how the arm was pivoting up where the latch handles were and the little space above the pivot point and.....

Voila! A hatch "holder-uppper". This is a piece of teak with the center rounded out to about the same diameter as the aluminum hatch arm most of the way along it (boy, those Dremel tools are great!). At the other end, I narrowed the wood thickness to the same width as the available space above the arm pivot point. A little hole, and a little brass screw -- done.

This is what the holder looks like when it is in use. You can just barely make out the screw through the plastic at the top where the handle is. The other end rests against the twisty thing that normally keeps the arm from sliding in.

When I am done, I just push up on it, and it stows itself just above the arm, resting on top. The only drawback is that there is only one setting for "openness". But I can always use the twisty thing for those times when I want a different setting. .