Day 113 Swim platform area
Cutting the shape for around the swim platform was difficult, at least the idea of it was.
How could one take a shape like that and sheer off a nice line? Origionally I had planned to just run a peice of flatbar around to the bottom on each side, coming off at a slightly more vertical angle than the plate coming into the transom. But then it became evident that this would cut off a lot of the swim platform.
The solution was to force the flatbar into a twist as it left the center by pushing out on the bar as it passed the radius. It wasn't hard at all just tapping it out with a hammer while securely clamped at the top.

Cut away using flatbar as guide
The edge near the top needed to curve into the 45 plate so instead of trying to force that in, I just left it and rounded it by eye afterwards. The reason I didn't want to run it in hard there is because the rest of the cut is a curve, so to retain continuity the top should be too.
Wow!! -at last those horrid sharp corners are gone !

The next thing to do is put the swim platform in.
Because of the 'V' in the aft area, the platform will have to sit about 8" above the center to get any reasonable width. Flat things seem to have no place on the hull of a boat but this was almost unavoidable!
First the transoms curve had to be derived. This was easy as we still have the piece that was used to curve the transom.

Next the sides point inward as they move aft. As the width of the platform was to be 6 feet, and the curve length is to be 100.5" , the length between the transom and the edge of the platform where it meets the hull on each side should be enough dimensions to draw it up. I took a perendicular tangent measurement off the transom to the point where it meets the hull and the measurements came true!
These lines also have a curve which had to be just roughed in for now. In the photo to right the tips appear to be nipped off but that's just because we didn't have any plate longer than 8 feet.
When we put it in place it was quite drastically oversize, so trimming and grinding can bring it in closer. Something we hadn't considered was that the platform should have a slight tilt downward to prevent water being trapped in the corners. Oversize is a good thing!

Now the aft is sealed in, there is nowhere for the cables to run in ! A large hole was cut where a hatch will be, and a stand (of flatbar) was welded on to stop the rain from getting in.

Day 113:
8 hours: Cut aft curve, made swim platform, welded the hull