I launched w/o a plug, tied off the 15ft tri hull chapparal walk thru boat talking with the wife and we walked off to park the truck, quiet ramp no traffic so we were in no hurry. Walked back to find the boat sitting on the bottom (luckily still on the ramp part and not pulled to the end of the dock like I would do on a busy day, full almost to the gunnels, gas tank, cooler, tackle box, floating. NO bilge pump. I climbed in, put the plug in from the inside and started scooping out water with a 5 gal bucket. When I felt the boat drift I started it up, had the wife climb in and took off as hard as it woukld run 1/2 full of water. Pulled the plug from inside and let the suction of moving pull most of the water out. We laughed about it and went fishing. If my vent had been open on my portable tank, or my battery mounted on the floor and not high on the transom I probably wouldnt have been so lucky.
I never disconnect the bow from the trailer until I am at the waters edge, I undo the rear straps, get loaded up with w/e I need to transfer from the truck then back down to the water, with just enough room to unhook and not get my feet wet, then I back the rest of the way in. I am usually alone, and most of my boats were "float on" trailers, so it takes more work and more time but I dont care, let em yell..