Don't give up on JP's stealth Carbon masts for watertight , I got one on my stealth 18sxl and put it through thorough inversion testing last year including total upsy doon testing , not a drop , infact to my embarrassment at Grafham fast cats , capsized - onto side , got trap hook stuck on uphill edge of trampelene and was left dangling my shapely 18 plus stone 8foot off the water , wishing the mast wasn't soo bouyant , boat wouldnt capsize any further !!! to let me unentangle myself , boom too far away to stand on , guys inrescue boat were pissin themselves , but somehow I managed to free my bulk eventually and then right boat .
Final test was last race of season when I managed a bows over stern job landing completly upside down , it was amazing to feel the mast lifting the boat onto its side without my help despite my 18 stone on upside down tramp !

Well done JP with mine - so far no leaks, being a superstitous sailor i firmly grasp my wooden desk whilst saying this!