I installed two of the PW30 round ports and have had no problems with them. To install mine, I placed them at the center of the vertical portion of the v berth (top to bottom). Then I used the interior trim ring as a template and simply slid it toward the bow until I could no longer maintain a flat surface. I measured everything about 10 times, got the correct size hole saw from Lowes, took several deep breaths and cut the holes. I sealed them with clear marine silicone and used stainless hardware, with flat washers and acorn nuts on the inside. They look great inside and out and have never leaked. I would gladly get some measurements but I just put the boat back in dry stack for hurricane season. I sent some pictures to Gene at Mobile East Marine and I'll see if I can find them. If not, I'll take some this weekend and post them for you.