Masts

You can sail a stayed rig by the lee but it is more difficult and not as effective (you need to let all the kicker off, drop the rig tension back to allow the leach to twist out far enough).

Personally I think it give an unstayed slower boat a poten weapon downwind having the flexibility to go by the lee rather than gybe. It can be used to good effect against 'faster' boats when trying to gain a tactical advantage.

Sailing by the lee is very straightforward with many stayed classes.  If the sail has a reasonable amout of roach as we have on hte Blaze it is very fast and the most practical way down course in cetain conditioons.  You simply ease the kicker and the top of the sail,  supported by the full length top battens goes forward.   

A few years back we were doing this in the Blaze class anyway but then Steve Cockerill raced with us and showed exactly how it should be done in waves.  Just a variation of the Laser approach really and very effective with a longer mast and modern sails - and great fun.   

Generally stayed masts offer a very great deal of flexibility.  I would also argue that they have a greater range of potential adjustment than unstayed to suit all from relative lightweights to relative heavies.  They also allow a very much slimmer and lighter mast section to be used all other things being equal.   Combined with a switch to carbon there are very major gains by switching from a standard alloy 'teardrop' mast such as on the Blaze to a slimline round carbon section with Halo.  These efficiency gains are possibly equal to or maybe even exceed the performance gain of the larger sail of Halo in isolation (with even greater supported roach btw).  I do not think we could do anything like the same thing with an unstayed stick.

As has been said already stayed rigs are fairly universal with performance classes carrying more than one sail or a trapeze.  D1 excepted ?

Unstayed masts are great for certain classes but not all and the real performance ones can be rather pricey - a factor that is also difficult to ignore.

Blaze720

The paper was particularly blank. Prob more a 75- 80kg person's boat right now, but smaller and bigger versions of the rig in the pipeline...

Another well-engineered unstayed rig. The main thing is that kicker tension is the key sail control as kicker tension, mast bend, sail fullness and leech tension are inextricably linked. You can't have a tight leech for pointing without flattening the sail off for example.

Downwing the unstayed rig makes life interesting as gusts bend the mast forward making nosedives more likely. Unlike stayed masts we use kicker tension to depower downwind (bend the mast and therefore flatten the sail) whereas it's more normal with a stayed rig to blow the kicker downwind (on boats with kites at least) to depower.

Pic by www.malcolmlewinphotography.co.uk