When the anchorage gets bouncy sometimes it helps to put a little slack in the bow and stern lines. Use long spring lines and keep them snug.

Tim,
Let me offer a slightly different idea. Assume that you put your anchor out, as you are the larger boat. The spring line from your midship cleat to his primary winch should hold just about all of the "weight" of his boat. If you and/or he don't have midship cleats, you should install them. On the toe rail, or just inboard of the toe rail. The opposite spring line from his midship cleat to your primary winch can be a slack. It doesn't get much use. Adjust the bow and stern lines so that there is some slack in each, with the bow having slightly more slack. Adjust the spring lines so that your spreaders are not in line with each other (for obvious reasons). If you play with the adjustments, his boat should settle off yours by 6-12", and pointing slightly more to leward than you. The anchor line should be slightly off your bow, opposite the side he is on. The wind should keep your boats apart, and the 6-12" between the boats can be easily crossed when you want to. With currents opposing winds, or huge wakes of passing boats on the beam, all bets are off. Lots of fenders are a must. I've been rafting with friends of mine for many years, with different sized boats, and this arrangement has worked well. Hope this helps.

Tom,

You continue to be an absolute treasure of information, thank you for staying with our organization even thought you moved on to the C400. My depth of knowledge of our boats be it technical or operational, pales in comparison to yours, your input is greatly appriciated

Thanks again.
Steve

Steve,
Thanks for your kind words. A lot of what I know comes from making mistakes for longer than many people have been sailing!! :-)

No one has made the obvious observation to a solution for this problem.... tell your friend to get a C36 and the problem goes away!