What is the proper method for towing an inflatable dinghy behind a sailboat? Should the dinghy be towed from a single line or from a bridle? What is the proper length for the painter when towing?
Dan Dickison responds:
Thanks for your question. Everyone has a little bit of a different take on this topic, so no doubt you'll read my answer, tell your friends, and then they'll say 'don't listen to that guy; he's wrong.' That's the nature of this beast. Nonetheless, I've paid fairly close attention to this topic since I once lost a dinghy while towing it, and I vowed never to have that happen again. So here are some basic points that should help you when towing your inflatable dinghy:
First of all, never leave your outboard engine attached to the dinghy if you plan on towing the boat in anything other than absolutely flat water over very short distances. Even then, you might encounter a vessel's wake and have problems keeping your dinghy from getting tossed around. It takes a little more time of course, but it's always prudent to take the engine off and bring it aboard the mother ship. The same goes for oars and other items that are apt to come loose if the dinghy bounces about (cushions, bailers, etc.).
With an inflatable, you want to make sure that you're not putting all of the towing load on just one fitting. I'm in favor of using a bridle, that is one line from the mothership that splits through the lead D-ring near the bow of the inflatable and runs aft on each side of the little boat back to a more secure purchase, like an eyebolt in the transom. Never simply use the dinghy's bow painter if it's only made off to the lead D-ring near the bow; that's just too much load for that ring.
Now you've got two options regarding how long to make your tow line. Some sailors find that inflatables behave best if the tow line is drawn up close to the transom of the mother ship with the bow of the dinghy out of the water and the dinghy resting only on the aft portions of its pontoons. If your inflatable is over 10 feet in length, it's probably going to be unmanageable to truss it up in that fashion. You'll be better off towing it well aft of the mother ship. The trick here is to get the dinghy in synch with the mother ship by letting out enough line so that the dinghy rests just on top of the second wave aft.
In most cases, you'll shorten the tow line for entering or leaving crowded harbors or well-trafficked areas. Then when you're out in open waters you can lengthen the tow line so that the dinghy stays in synch with the mother ship. Also, a lot of sailors double up and use two tow lines if they're going to be towing their dinghy for long distances, and particularly if they're going to be towing it at night.
Just one other caveat about towing: make sure you know at all times where the tow line is. If you engage your engine and forget to shorten the tow line, you'll be running the risk of having that line wound up in the prop and shaft. Most sailors only suffer this problem once.
Here's hoping this information is helpful. Depending upon what make of inflatable you have, you might also want to check with the manufacturer regarding the recommended towing methods just in case your boat has a different system for attaching a tow line, or the recommended towing method has any bearing on the dinghy's warranty or your boat's insurance.