M_Boats: Problems

I took my M-15 out for the day today on a nice lake in Oregon. But I discovered some issues that I need help on. The biggest one was getting the boat back on the trailer. It seems that the outboard weighs the boat to the starboard where it is mounted. With that small lean to starboard, the boat would not move up into the trailer in a balanced way. That ended up making it impossible to get the boat onto the trailer with the shoal draft keel resting on the rubber runners down the middle of the trailer. Instead the boat came out of the water with the keel resting outside the center of the trailer where its supposed to rest. I got in the lake several times trying to center the boat on the trailer. Am I missing something?