I will post the basics and better pictures as a photo forum article IF I ever finish, but for now I thought I'd post my progress to date. Hopefully this will be good reading for some of you, if not it will be long and unbearable. I noticed a slight depression a few mm's down and about an 1/8 of an inch width all the way around the oval aluminum mast base, and had some slight cracking around the cabin top step. I thought I would just be replacing the step core, as the PO had told me it had already been repaired, and I suspected if there was a new issue it would not be widespread. In opening up the top of the step, I found this... the previous repair had been to cut through the step, and the cabin roof, and replace the core with 2 layers of 1/2" hardwood ( I believe oak ) in a trapezoid shape. No glass or epoxy between the two layers. The 2 pieces of wood were wrapped in fiberglass cloth, but it had only been wetted out on the top and bottom, not the sides. The sides of the remaining roof core ( balsa ) were scraped back a bit, but were not sealed and filled with epoxy, but spray in expandable foam.... For reference, there are some pictures at: http://www.geocities.com/attiraj/H30maststep.htm So the step started leaking again ( I'm guessing before I bought the boat ) water migrated into the rest of the plywood layer of the step AND through the cabin roof layer of balsa. I ended up cutting out a large portion of the deck after lots of tapping. The piece cut out includes the elevated mast step. The rotten and water soaked balsa was everywhere. One important thing to note on this. The " T " shaped mast step is hollow on both sides. Meaning there is a space between the top of the roof deck balsa and the glass bottom under the plywood of the step. This is VERY bad as it allows leaking water to spread across the top of the balsa in a large area. If just sandwiched balsa core, my understanding is it take a long time for water to spread through and soak then rot balsa. In this case, it had spread far and penetrated. The basla was totally soaked. I have since cut out tons of balsa and replaced, and have built up a 15" by 12" pad of solid glass under where the mast sits. I'm just under the thickness of the cabin roof balsa right now. My dilemma is trying to decide on the next step. My choice is: 1) do I replace the skin cut off, and rebuild the core of the mast step with all glass or maybe an aluminum plate? 2) OR do I use new cloth to layer the whole deck roof, and build up a new mast step that is more of a square pad of solid glass to get the height right ( like the Cherubini H33 ). The usual prescribed method would be # 1, but I have found that many areas of the removed deck piece had not been originally wetted out, and in some areas that unwetted mat looks " rotten ". In addition, the surface of the core is quite uneven ( from the unevenness of the inner skin ) and so I am concerned about getting good surface adhesion when replacing the deck piece. I would drill some holes for air pockets to escape, then use lots of sand bags to try to evenly weight the deck piece back on. Could lead to a bumpy surface though. I think vacuum bagging is above my comfort level, and would be even more difficult given the large area to seal. The benefits I see to # 2 would be to ensure an air pocket-free solid deck sandwich. Great adhesion, and likely a better finished surface. Also eliminates the possible issue of the strength of the areas of the deck piece that were not originally wetted out ( although I would obviously wet them now before replacing in # 1 ). The drawback to # 2 is replacing the " T " shaped deck step with a more H33 like smaller square step. Rebuilding the " T " over a new deck surface would be more trouble than just living with option # 1. My concern is that the " T " shape is structural, and therefore I need it. I'm leaning to thinking it is not structural though. It was cored with plywood, and was hollow to the deck core on the sides. Maybe in that configuration it is necessary, but in the case of a solid glass cabin roof and solid glass pad, I think that may negate the need for the " T ". I actually have the question in to Hunter Tech, but given their situation they definitely have other, more pressing issues at hand. I'm also not sure they will want to offer advice given the age of the boat and the nature of the question. Even though I think #2 would be easier, I'm leaning towards the "safer" route of # 1, but this changes hourly.... Any naval architects out there?