All I know about Laser Sails.

Laser sails have gone through several iterations over the years.

The original cloth was a 3.2oz dacron. This was eventually changed to the current 3.8oz dacron but the cut is the same as the original. There may have been minor changes over the year (adding a little clew re-inforcement etc..) but nothing fundamental.

As a result the sail just stretches almost as soon as it is put on the mast. You need to us the controls a lot to control the shape and bend the mast. With such a light dacron cloth it simply stretches each time you use it and continues to do so until eventually it is so stretched it becomes useless.

The new 'Mk2' goes some way to addressing the cloth stability issue but using a cut that helps to stabilise the cloth. I am surprised they did not go for a mylar leech as this would make them last even better (IMO). Sadly, as with all things Laser, they have been arguing over it for a number of years now and they are getting less and less likely to agree it before another re-design is needed.

The 8.1 sail does address this as it is made from a slightly heavier dacron and has a mylar leech. My first 8.1 sail lasted 3 1/2 years until I decided I needed to replace it. I did sell it on and it is still in regular use but having a newer one definitely made a difference.

For one, I assumed that it was generally known. Secondly, at the very worst it means that you could get into the top 25 at the worlds with one old borrowed sail, one new sail, and one charter sail.  Whichever way you slice it, it demonstrates that you don't need a new sail every regatta or so to be competitive as some people claim. 

I haven't sailed Lasers seriously for years so I'm no longer top 10 nationally, but I have got into the top 15% or so at Masters champs with a second-hand sail and a hull about 30 years old, with a best heat of 2nd between two world Masters champs. It is a fact that you don't need new gear to do a lot better than average. 

Yes, the Laser sail stretches - but stretch is not always a bad thing per se. The Laser is actually very slow if you rock the mast forward to get an even tighter leach, so it's not as if tighter leaches are always faster. Plenty of top sailors don't keep the leach as tight as possible all the time - for example my arch rival was a 3 time world Masters champ who would ease vang in about 15 knots of breeze to reduce leach tension for faster footing. Of course downwind we're trying to twist off, so there's even less penalty.

Some top sailors say you should train with new sails, but people like Michael Blackburn used to train on old gear a lot of the time.....of course there's probably people who reckon he doesn't really know Lasers because he has only got an Olympic bronze medal and two world titles to his credit as a sailor, and a gold medal as a coach.

It's very, very hard to guess, but if I had to take a stab at it I'd reckon I lost 4-5 places at the last Masters nationals because I was using a sail that was second-hand when I bought it about 8 years ago (and has since been fairly lightly and carefully used) and a 25 year old boat with crappy foils. But that could all be in the mind - in three other titles I've come in low on practice and speed and started blaming my old sails - and in all three cases I ended up fastest or second-fastest which proved that it was practise that was the problem, not the gear.