[Ronmar]

Lou, I think the older open transom boats have a separate deck and hull with an airspace in between forming a large flotation chamber so the boat goes up and all the water flows out the back.

I am guessing that your boat dosn't have closed seat tanks? The newer FJ's have closed seat tanks and like the 420's and most other modern small class boats, float like in the below linked pic when knocked down. That is one way to dewater them when swamped. You stand on a seat tank, grab a shroud and pull the boat over and all the water flows out. Of course if you don't have closed seat tanks, this won't work well for you.

.bing.com/images/search?q=1967+flying+junior+sailboat&qpvt=1967+flying+junior+sailboat&FORM=IGRE#view=detail&id=D5004E376903906608462D77D9A44C43A798C56A&selectedIndex=254]1967]1967 flying junior sailboat - Bing Images

Sorry, can't post links till I have 10 posts or more, cut and paste this one and add a www to the front to see the pic I am refering to.

You have a couple of options, one is to enclose the seats and form tanks to get similar performance, but they need to be watertight to increase your internal displacement/lower your internal water capacity.

You can add closed cell foam or air bags to accomplish this but that adds weight and may form places that will not like to dry out fully.

You can make some foam seals out of Ethe-foam(Polyethylene foam) that you can jam into the centerboard trunk and the holes alongside the tiller if it passes thru the transom, to better seal these ports that are below the waterline when swamped. This might allow you to out-bail the inflow with a bucket sized bailer. It is easy to cut with about any cutting impliment. I use a table saw which makes dimensioned parts real easilly.

OR lastly, If you are going to sail in rough conditions, get a newer boat that can shake off the water and be recovered when flipped under these conditions...

 

[Ronmar]

I would reccomend a 420. Not too heavy for single handed at a little over 260# Quite fast and can take some wind and weight(Im 220#). Easy enough to right and usually comes up mostly dry. It has as much(or as little) capability in the rig as you want to deal with... It has always been one of my favorites. It also has the advantage of being used all over the place so they arn't unobtanium. I found my current one alongside the highway 3 years back complete without trailer for $300. It was an ex club boat that the owner had purchased and used without any maintenance for many years, so it needed some work(beatup foils and loose/cracked centerboard cap). It was complete minus spinaker and trapeze rigging, neither of which I typically use. I have well under a grand total into it including a new trailer, but I can do fiberglass and gelcoat work. Teaching the grandkids to sail with it now, in fact they had their first flip and right lesson last week at the dock. Having watched quite a few utube videos on the 420 now, they are hinting at wanting a trapeze