Thanks Richard for your helpful replies which are still on topic of how to make the hatch watertight. If I went for that system, I might be able to incorporate a round Hasler hatch with rotating spray hood into the sliding hatch as well. My present sliding hatch and garage, does not allow for that, but your idea with rollers would mean I could remove the garage and the hatch when closed would still be watertight. Good one I like it. Whilst Jesterchallenger might feel this all too much bother and is entitled to his opinions, clearly Guy Waites with Red Admiral, Roger Taylor with MingMing and Pete and Annie Hill with Badger thought otherwise.
After I read Roger's books and saw how he had modified MingMing, I built a plywood mock up in the shed to suit my Hurley, but whilst I could easily get below decks via the houdini hatch, I could not for the life of me get out again. I can only surmise that Roger's dimensions and my own are somewhat different.
Sorry guys. Links are bad and just go to closed sites. So just bin that one!
'Whilst Jesterchallenger might feel this all too much bother...'
You misunderstand me - my hatch is secure and reasonably watertight in all normal conditions. The washboards are secured with bolts AND lanyards so they cannot be lost in the event of a knockdown or full 360. The sliding hatch can be secured from inside or outside as well to prevent this sliding back in extremis. However....unless the washboards and sliding hatch have secure neoprene seals it is very difficult to prevent the ingress of small volumes of water in bad weather - bearing in mind that when a wave strikes, the hydraulic pressure is similar to a high pressure fire hose - and I don't know of any boat I've been on that will withstand this without some sort of leak through the boards/hatch. And if you need constant access through this hatch, the seals make the sliding mechanism much more awkward.
I have no headsail furler and therefore continually need access through the companionway carrying a bagged headsail, quite often in the worst weather, both upwind and downwind. My sail store is the forecabin and whilst I can drop a bagged sail quickly through the forehatch (you do have to be quick!), dragging the next sail back up through this hatch is next to impossible. My point was that to make the companionway 100% watertight is only realistic when you don't need continual access to the deck to sail the boat (like Ming Ming, Jester etc). And in reality, the amount that gets in through the boards in bad weather is quite small (but none the less annoying for that!) unless you mistakenly leave the hatch open as I did whilst being knocked down. In the YM crashboat rollover sequence, it looks like a lot of water pouring in, but I would suggest it's an irritating but not life threatening amount. It's a good idea to think about protecting the chart table and electronics from such a downpour - I have now fitted a perspex screen to my chart table specifically to address this.
A watertight companionway is an ideal that's quite difficult to achieve if you need constant access through it. And if you do, the small amount of water that gets through is no more than an annoyance - much the same as walking through the cabin with wet oilies and a wet sailbag dripping water everywhere. Unless you can seal the cabin up completely, any small boat is going to get wet below in bad weather I'm afraid.
I would add that whilst rare, a knockdown is not unheard of, but shouldn't be too serious a happening although alarming, and certainly a wake-up call to your boat management. A 360 roll on the other hand is extremely serious in even the most well found boats, but thankfully most unlikely if the vessel is well managed. However there are issues of preparation for the latter that should be undertaken to prevent serious personal injury to the crew, but perhaps that is a topic for another thread.
Leaving the YBW forums after continuous accusation of misleading and being utterly wrong on everything.
Oops, is that me? I thought I had expressed an opinion and not made any accusation of anything, but if you took it as such, my humble apologies, it was sincerely not meant that way.
Passage plans rarely survive the first gale.
Dear Jesterchallenger. Please do not leave the forum. You made some very valid points about the hatch and the limitations on waterproofing, given the need for constant access when sailing a bermudan rigged boat. I accept this and having sailed bermudan rigs up until lately when I bought my junk rig, I agree with you whole heartedly. I suppose the comment about water down your neck giving you a wake up call was I felt rather unnecessary, but that is just my opinion. Thank you for your comments, all of which were taken in good faith as I am sure that is the way they were intended.
very interested in reading the hatch stuff. I'm about to rebuild a companionway hatch on a gaffer. As the height of the wooden coach roof is only about 16 inches I was considering doing away with washboards and using a Maurice Griffith style double combed hatch, but somehow making it lift and then slide forward. I can think of a number of ways to do this but have yet to stumble on the easy, practical -and probably obvious- way to do it!
Id be grateful for any thoughts.