I'm still trying to find a pic. of my tramp. I have towed a kayak and as long as the water is flat I had no problem. When the waves start,water gets into the yak and you know what happens next. The opening needs to be covered to keep the water out. As far as tacking goes, I've tried a bridle with a block and a couple other things. I found the best way was to tie it near the center up close and use the wake the boat produces to stabilize the yak and if you get it on the right part of the stern wave the yak is almost surfing which reduces drag and makes tacking easier. The type of yak or how well it tracks can make a big difference in how you tow.
The nice thing about towing the yak is you have one more toy to play with when the wind dies.

Mike Catley