Fedor, sorry I did not reply, your message got sent to Spam.  

The mast in the middle of the tramp is a requirement with the triscarph configuration as there is no lee hull to put it in.  Benefits are:

the lee hull can be lower and lighter as it does not see the rig loads

no bearings to buy and fit

little more righting moment (quite a bit on BL as it is so light)

easier to raise/lower and possible to cant and rake. Raking means a much bigger mainsail can be carried without an increase in weather helm.  Canting lifts the lee hull in a breeze and allows the sail to fall to leeward in light air.

No idea if it will prove to be better or not.  That is why I am playing with it.

Launched BL yesterday and got it foiling.  Only under motor and without the rig and tramp, but a step in the right direction.    One of those things that was a big deal before it happened, a bit of a non event afterwards.  

Took about 90 minutes to carry the components across to the beach and assemble it, much of which was playing with temporary ratchet straps to hold it all together.  Then motored it round to the canal and fitted the rudders.  Locked the front one and steered the aft one with temporary strings.  The hulls lifted at ~4 knots of boat speed and lack of hands to steer and control the outboard limited top speed to 7 knots.   Foils are 40 grit sanded and still need work on the leading and trailing edges.  ​

Back in the garage to beef up the beam sockets, connect the steering, install the rig and clean up some of the shortcuts.  

Foiling video on http://harryproa.com/?p=424  and https://www.facebook.com/Harryproa/?ref=page_internal in the next couple of days.