In another discussion discussing what type line to use for towing... I noted the length of towline is related to distance between wave peaks.
Essentially you want both the towed and towing boats to be cresting the waves at the same time to reduce the tendency of the line to cycle tight-slack-tight-slack....
The towline should have some indicator as to when you are in danger
of snapping it. The forces on the line can be huge.
If the towed boat
is surfing down the wave as the towing vessel is climbing a wave then the line slackens then as the towed starts climbing the towing will be surfing down the face and you'll suddenly have many times the tension on the line.
Good formula to snap a towline.
Then there's how you hook the lines to the towed and towing vessels and putting a weight (can be a length of chain) in the middle of the towline to moderate the tension cycles (which will happen somewhat, no matter how well you space the vessels)
And then there's the speed of the tow. Things get more unstable and more dangerous as you go faster.
That's just basic outline of SOME issues for towing...
If you plan on towing at speed at sea, you'll want to do a lot of research
on how to do it safely.