1. 600 masts break alot so there's a ready supply.

2. Cherub has a relatively short mast-cap rule. (Don't get me started) 600 mast seems to be about the right height.

3. The single spreaders normally get removed, it's not difficult to add two pairs.

4. It doesn't necessarily have to be stumped. I think Iain did this on Suicide for his own reasons.

The 700 mast is a much better section and can be supplied exactly the length you need by Superspars.  It is very stiff sideways (the most important thing on the planet to get the thing to work uphill) and pretty light (although a few hundred grammes heavier than a C tech) cheap too.

There are two types of 600 mast, the aerofoil section Angel, and the 3 piece SuperSpars made from a main tube, a top section and a separate track.  Suicide Blonde has an Angel mast.

I think that the Angels do have a reputation for breaking, however even with much more rag than a 600 there's an awful lot more holding it up and we have not broken it yet, despite some serious abuse where we've snapped poles and damaged chain plates.

The single diamond spreaders were obvioulsly removed and two sets of home made carbon/balsa spreaders glued on.  The mast does not have lowers, but it does have forestay, mainshrouds, D2s and caps.

I don't have the exact measurements, if you need them let me know and I'll take a tape measure with me next weekend to Weston, however the mast is in it's "short" configuration, with the alloy foot removed, and the very top 1" or so cut off (the bit that has the halyard pulley on normally).  It needs to be stumped to get to max mast height rule, so conveniently an RS800 mast, with it's foot glued on the old hog, and chopped off flush with the top of the existing 800 gooseneck worked fine, I think we are a measly 14mm off the maximum.  There were other reasons for going for a stump rather than adding the length to the bottom of the mast, but it all works fine.  Arguably the mast is actually a bit stiff, but this is more to do with how it's rigged rather than the mast itself.

On my new boat, I will actually be using another 600 mast as the rig, as this will make a big difference to the build cost, and to be honest the current rig has worked so well I don't see any reason to buy brand new.  However this one is a SuperSpars mast, and I'll do the caps a little differently, just going through to top spreaders only, and either going adjustable back in to the mast, or going 49er stylee to the chainplates.

Cheers

Iain