I am club racing 3310 a composite NSM 2. She has a built in back tank and one in the foredeck. However when we capsize..(which is rather too often),she barely floats and is certainly not redeemable by anyone but the rescue boat.Any ideas on what I can do to increase bouyancy?

THANKS Rod.

Before doing anything drastic, are the tanks airtight? Merlins do float low when full but you should be able to clear the water when you sail off.

see the attached thread for further discussion /commentary /ideas

http://www.merlinrocket.co.uk/forum/main/topic.asp?topic=3249&forum=main&comments=14&page=1&sort=5&order=1&search=3463

Also, Merlins (and 12's) won't sail off full of water unless the centreboard is half up. Forgive me if you already know this but I thought it worth saying.

Last time we went in (Bloody Mary, bloody cold!) the transom was definitely well below the water before we got going again, this used to bother me and no longer does, once you have a bit of way on the boat comes up and the water goes out of the transom flaps (which you probably don't have) & bailers.  But it does need a bit of breeze and enough space, which is always an issue at my home club, Hampton.  Another tip - make sure the kicker is off completely before you right the boat, much easier to get up and much less likely to get knocked back down again.  You need the board right down so you can stand on it, I've never fussed too much about getting it up once upright, but can see the sense in it.

Thanks all , didnt know about the centeboard having to be half up..relatively new to this but all good advice..the boat is slo low in the water its hard to see how it will ever lift out.I could eat less pies of course...

Just re-read the thread from 2012, and think the advice from 'confused' is spot on...try harder and get on with it.Its good to know it isnt just me though, looking forward to next inversion..

The other bit of advice from that thread was about getting going on a fine reach (more stable) & bearing away as the speed picks up and the boat empties, the kicker comes back on as you do this

Backing the jib also helps as does the crew blocking the centreboard slot. 
The theory is that a boat rotates around the mast and since the boat is full of water there is more weight pushing it with the mainsail so the jib has to be pulled further the other way to counter it. It seems to work in practice as we've successfully sailed out and finished races after having everything behind the shrouds below water!

Interesting...firstly, according to the Merlin Rocket Book Of Words 3310 is an Omega-hulled NSM1, not a 2.  I don't remember any of these being built with an aft tank (?) so it may be a later addition, possibly copied from the Summer Wine.  It might be worth having a look at that tank. Is it airtight?  More particularly, is it full of foam? Some bright sparks many years ago thought that blowing their tanks full of the expanding foam you buy in a spray can would solve the problem of leaking built-in buoyancy (I've even seen it done to buoyancy bags!)  The trouble is, the foam breaks down after a while and, rather than trapping air and excluding water, actually soaks the stuff up like a sponge.  Not the best recipe for a buoyant back end...

There were indeed a number of Glass NSM 1's built with rear tanks and ply tops. To my knowledge there were no NSM 2's like this until the full Plastic Wembley One Designs.

3310 is an Omega Glass hulled NSM 1 with timber Decks built by Rowsells. It is quite possible that she had a rear tank as allot of these did. However there were various tank designs and allot of the bouyancy is quite high up and so the boat will sit low in the water. However, bailers open and sailing slightly off the wind with your plate half up and with enough wind she should rise up very quickly. The issue comes when you don't have enough wind, in this instance spill it quicker and stay up right ;-)

I had 3290 - Mornington Crescent - decked by Guy with a rear tank. We also built it without a thwart, a la Dick Batt's Vampire. As I recall the curvature of the tank gave Guy a few problems, and measuring the buoyancy gave Stu Nixon a headache or two.

Nick

Mornington Crescent is still at our club in Cookham and is a pretty boat, also fast. The guys who own it have capsized once or twice and seem to be able to sail the water out ok.

All great stuff, and you are right she is a NSM1 not a 2 ..getting my wires crossed.She came from Essex and also came without a thwart. We put a thwart back in, Or to be more exact Jim Woodward put a thwart in.

The rear tanks are just empty space and seem to hold air ok. As you say, a very pretty boat, and I think I just need to grow some bigger bxxxs and get on with it! But thats the beauty of these forums, is that you have all done it before and now I know it is possible will sort it out. I think though that the overriding theme is that below a force 4 it is a swim job?

I can see how it might be possible, but you shouldn't really be capsizing in less than a Force 4 should you?!

It's Time in Boat that's needed - capsizes are much more likely in the first year of sailing a new-to-you boat whatever the wind force. 
Alan - we'll be keeping an check on you as a candidate for the club's "Radox award" - for frequent bathing! :-)

Pat,  I've been trying hard but not bathed yet!!