Well, it was all very nice to bask in the glory and I like to be thought of as clever and creative, but I have to be honest: it was Alan (Zebedee), who voiced the idea a year or so ago.  I can only take credit for having remembered it.  :-\

Annie wrote:

David D wrote:And again being a circular hatch I can't pass up a circular disk up thru it to close off externally.  I would have to have disk stored on deck on a lanyard, or a folding disk?

David, have you ever come across those little pressure cookers with the lids that have to be slid on and then turned through 90 degrees to secure the handle and lid?  The lids are what I would term 'oval' although no doubt that is the incorrect geometric term.  To me, the obvious way to make a Hasler-type, clamp-down disc over the opening would be to copy this idea.  You could then put it up from inside, turn it and clamp it down.  Personally, I don't see why you couldn't use over-centre catches for this, too.

Excellent idea, Annie. Award yourself a gold star. The mating edges of the rings have to be accurately circular, so as to be free to rotate, but the aperture through the rings can be any shape you like, and oval or elliptical sounds good to me. Why has no-one done this before?

Arne wrote:

Yes, Annie,
you can of course alter the hatch arrangement any time you like.
Just a little word in defence of the sprayhood: Mine is held up with only one line on each side  -  no buttoning necessary, so it can be raised or lowered quickly. More often than not, I sail my Ingeborg with the sprayhood lowered, but when sailing upwind, and Ingeborg starts spitting spray (which she likes), I raise it. It also lets me stand up in the hatch when cooking or washing up. Remember, Ingeborg’s tiny cabin (139cm headroom) puts me on the borderline between serious boating and camping afloat (..rather closer to the last...)

You say you lower your sprayhood: well you are very much the exception to the rule here (but aren't you generally?).  So often when I go on boats it is perfectly obvious that the sprayhood hasn't been lowered in years, if only from the amount of clutter gathered underneath them.  The excuse is that folding it damages the plastic window ...

However, even if I wanted one, I don't think it would be ideal on Fanshi: they are much more suited to boats with side decks that allow you to fasten the sprayhood securely to the coamings and permit access down the side decks when the hood is up. 

David D wrote:

As you know I am exploring inserting a pram hood in my new sliding hatch/ conventional companionway Badger.

Annie and David T make excellent points.

If I can ask them directly, does water get in thru the seal at the rotation rings when water washes past?

I think you mean between the dome, or flat cover, and the fixed ring that retians the rotating ring? A downward facing lip, or a self-adhesive foam sealing strip, on the dome or cover, if it's a problem.

David T your security hatch is under the hood between 2 layers of hatch.  Where does water that hits that from rain or seas go?

There are drain holes in the main sliding hatch, out to the sides, and the inner slide has a downward facing lip on its sides. But solid water doesn't reach here when the hood is up. The only issue is when you forget to put it up, and it rains overnight; then you get a nice refreshing shower when you push it back in the morning. But note that to use this slide, the main hatch has to be twice as long as normal if the internal slide is to be fully enclosed. When I put in the mizzen mast, I had to shorten the main hatch, and then the internal slide protruded out of the front of it when slid open. When I took a green sea over the bow, some of it would find its way through the open front, along inside the hatch and down my neck.

I do like Annie's dome that clamps down but that won't work on my sliding hatch.  And again being a circular hatch I can't pass up a circular disk up thru it to close off externally.  I would have to have disk stored on deck on a lanyard, or a folding disk?  It could be more robust and dog down harder for security and weather tightness.  Is that the thinking David T?

I think the practical solution is a flat disc that is stored below, and can be passed out when the hatch is slid open and the washboards are not in place. A folding disc would need a waterproof hinge - not easy.

Teetering on the edge of small spray hood/ dodger with windows just the size of the hatch VS Hassler pram hood here.

All in all, starting from where you are now, I think the small sprayhood, with a total angle unfolded of 170˚ (or such that you can still see aft), with buckles to partially fold it at 135˚ (rather than the total 135˚ of the Hasler pramhood), would serve you well and be easier to make than a Hasler or solid dodger. Unlike a solid dodger, you can lower it to get at the rig controls without full body exposure - useful in foul weather. I find mine to be quite serviceable on Weaverbird. Yes, the Hasler is the de luxe option, but this is a good second best.

Yes, Annie,
you can of course alter the hatch arrangement any time you like.
Just a little word in defence of the sprayhood: Mine is held up with only one line on each side  -  no buttoning necessary, so it can be raised or lowered quickly. More often than not, I sail my Ingeborg with the sprayhood lowered, but when sailing upwind, and Ingeborg starts spitting spray (which she likes), I raise it. It also lets me stand up in the hatch when cooking or washing up. Remember, Ingeborg’s tiny cabin (139cm headroom) puts me on the borderline between serious boating and camping afloat (..rather closer to the last...).

Arne