If you merlin is old or/and over weight, 
If you fill the rear bags and front tank with helium to offer positive lift, to put it back to the correct min weight, 
Is this legal, if yes, would it affect the performance, might it float higher after a capsize, rarther than normal air filled.

Help please, my brain hurts.

Perhaps we could try dagger boards.  I understand that much weight can be saved by removing the centreboard case and replacing with a dagger board+case.  It’s cheaper to build as well.

PS  If your buoyancy tanks leak from somewhere near the top the helium won’t last long.  If they don’t the answer is a marginal yes to both your questions (don’t know or care about legality as it’s rubbish idea practically).  You won’t notice the difference though.

Sorry, but this probably wouldn't work:

You would need more helium than the capacity of the bags or tanks. Look at the number of helium balloons that vendors hold - it doesn't lift them off their feet. Therefore the amount of helium required to create positive lift of say a twenty three stone  crew and their boat would be huge.

Now this is really interesting.  I am going to need buoyancy bags on Merlin 111 and have suddenly realised that all the Valentine's Day helium heart shaped balloons discarded as love has faded may be the answer. Legal - possibly. Clash with colour scheme - definitely.  Talk with a funny voice after you have blown them up - certainly.  Bye all - have a great weekend.

We looked at this with the help of Imperial College long ago it would not be illegal or wouldn't have been but the lift would only have been about 8 oz in a full set of Bouancy bags!

Helium in buoyancy bags doesn't work - molecules to small and leak through the upvc.

Jesus Christ!!

You lot need to get out a bit more often!!

No we don't (want to go out!) not in this weather,( It's too cold even for hunting.) it was a serious study and part of Rodney Pattison's first Olympic (1968) campaign - you may recall Supercallifragilistic   etc etc was seriously over wight, however didn't seem to slow her up! - they also raised the molecule bit I didn't mention it it seemed a bit too geeky but thank you for that confirmation. Incidentally - gas man- is there a membrane that would hold helium or is my air-ship doomed to sink eventually?

don't let them out - and dress them in the white dry suit with the arms that tie round the back!

Of course it is best to put a vacuum in your front bouncy tank. 

However if you are that worried, try sailing bare footed, as I think we neprene sailing boots must weigh a kilo or more.

I wish you'd stop posting these questions - the forum is getting so obscure it is affecting my brain! The other night I dreamt we attended an open meeting where Graham W was applying new PY handicaps to each boat, based on the ball-bearing block at the end of the spinnaker pole....

BUT ITS NOT DULL IS IT! It shows what an esprit de corps the MR Class has and how sharp the intellect of the MR Sailors is!

Isn't someone confusing weight with mass????

Don't worry Mags,  it will stop as soon as everybody's been sailing once or twice.

Then it will be back to "Capsized four times this weekend" and "Bloody good report on the open meeting" and "did anyone else see such-and-such puking over the road from the campsite on the weekend?" type postings.

Ah, the new season - Bring it on!!!!!

Of course, according to my basic understanding of the Special Theory of Relativity, mass increases as you approach the speed of light.  Logically therefore, trying to make my MR go faster by reducing weight is eventually going to be counter-productive.  Or have I been breathing too much helium?

That or Liffey Water intake!