Bimini on "Whale"
I bought an inexpensive bimini which was 6 foot wide, 6 foot long and 36 inches high. 36 inches seems to be the lowest that they sell. In order to get as much room as I could under the bimini, I raised the mainsail pulley at the top of the mast as high as I could. Then I found that I could move the gooseneck up 3 inches. After that I had to lower the bimini 3 inches. I did this by shortening the tubing near where it attaches to the coaming. This still left more than enough room to sit under it. When sailing the boom just clears the bimini.
There are 3 foot tracks mounted to the coaming. this allows the bimini to be slid fore and aft. The sailing position is aft. If it is moved forward it will keep rain out of the cabin. When I lowered the bimini by shortening the tubing it changed the geometry and the cover did not fit the frame properly. To make it fit better I had to do some sewing in the four corners. When the bimini is folded it is stored under the tiller at the back of the cockpit. It is on the lazarette cover but the tracks allow me to slide it a little forward when I want to get in it. I leave it there with the top rolled around the tubing and the straps holding it rolled when trailering.