Joyride;
Reviewing all the proposals, some are creative, expensive and some unsafe to the equipment not to mention the person while operating it.
What it will boil down to is knowing the lake well enough to make a determination if you can launch. Knowledge of the launch area is very important. A few pointers for you.
First, wood planks have a tendancy to float away which I have seen in the past. Yes I have seen drums used trying to float a boat into a lake but many times in disaster unless you know what you are doing. As for the ground under water, if it is too soft, trailers will get stuck and if winching out, there will be damage, so use caution if going that route. If there is any sandy bottoms and sand beaches, remember that wet sand compacts and is a better area to launch if you can get to it. However, walk the area in the water where to launch that there are no under water obstructions. Again, knowledge of the area plus you know how to do this are two main keys. Over the past 55 years to include as a dealer, I have seen a lot and the most important item, use caution, wisdom and above all else, be safe.
Dave Condon