Moving a Big Boat with your Tender - PassageMaker
A practical DYI for turning your tiny boat into a tug boat.

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My friends George and Ann have a lovely 50-year-old 44ft Hood/Maas steel sloop called Allez. When she was launched last spring, the old Perkins engine would not start, but they needed to get her to their marina on the other side of the harbor. That afternoon, I met Ann on the dock. She explained the predicament and asked if I would launch my dinghy and give Allez a tow. George is a wily old man: Ann is a refined, courteous, outhern Belle whose request would be hard to refuse. He needed a tow and knew how to get one. Somehow, I had to move their 18-ton boat, with my 10ft 6in dinghy and its 9.9hp outboard.

If you’ve ever tried to tow a big boat behind a dinghy, you probably found it was not as easy as you thought it would be. A bridle must be rigged on the dinghy, and this puts the towing point behind the engine, which can make it very difficult to turn. You also have no brakes, but must coast the boat to a stop, all the while trying to keep the bridle and tow rope out of the propeller. Fortunately, a solution to these problems exists in the form of a side tow, a technique that gives you much more control, thereby making it easier to maneuver.

Generally, it does not matter whether the dinghy is to port or starboard. The choice depends on where you’re departing from and where you’re going. In other words, you should place the dinghy where it will be the least in the way when casting off lines and tying up again when you’re finished. For maneuvering Allez, I put the dinghy on the port side, since it would be easier to get out of the first marina, and I planned to put her in her new slip bow-first with the pier to starboard.

Setting Up

How to set up your dinghy for a side tow.

How to set up your dinghy for a side tow.

For an alongside tow, you do not make the dinghy fast amidships. Instead, it should be secured well aft, on the hip of the boat being towed. This, in turn, puts the dinghy propeller well aft of the center of lateral plane—the center of rotation for the towed boat—and will let you steer the load much more easily.

Note that with the dinghy propeller off to the side of the towed boat, the dinghy will want to turn the boat in the opposite direction, both in forward and reverse. For this reason, you should also tie the dinghy with the bow pointing slightly into the towed boat’s centerline. This will make it easier to steer by counteracting the drag of the boat alongside.

Something else to be aware of: with your sailboat engine, when you go into reverse and add throttle, the propeller bites the water and quite effectively slows the boat. With an outboard, however, you have to be careful; when it goes into reverse, the propeller is biting into its own exhaust gas and can easily ventilate, or draw air into the propeller, which practically eliminates the reverse thrust.

When setting up to tow on the hip, it is essential that all lines be as tight as practical so that there is no movement between the boat and the dinghy. First, set up the forward spring line from the dinghy’s bow eye or the outboard D ring farthest from the other boat’s topsides. (The latter will provide an even more secure angle.) As you are doing so be aware it is not necessary for the lines to go to a cleat on the towed boat. You can also use a lifeline stanchion base, jib sheet winches or genoa sheet blocks as towing points.

Next, set up the aft spring. When I towed Allez, this line was also secured at the bow eye and then passed around a strong point on the boat. To tension the line, I used a trucker’s hitch. This gives you a 2:1 mechanical advantage to set the two springs very tight.

Finally, after fully tensioning the aft spring, set up a stern line and pull it tight. At this point, the dinghy should be secure and unable to move either forward or aft. It should also not be able to swing toward or away from the towed boat. Once they are securely tied together like this, I call the combination of the two boats, the “rig.”

Maneuvering

Outboard in reverse, towee backs to starboard, a result you can use to your advantage.

Outboard in reverse, towee backs to starboard, a result you can use to your advantage.

Now comes the fun part! Allez had to back out of a slip, turn 90 degrees to starboard in the fairway, go three boat lengths, turn 90 degrees to port, go 200ft and then turn to starboard into another fairway before we would be out in the harbor. Not surprisingly, when maneuvering like this, a person at the helm of the boat being towed can be a big help. If, on the other hand, you are singlehanded, maneuvering a rig can take a bit of practice. It is also vital that you secure the helm amidships. Fortunately, George was there with a couple of friends, which meant he could help steer.

After we dropped the dock lines, the dinghy (to port) started to pull and she backed right out of the slip. Again, remember that when in reverse the towed boat will want to back toward the side opposite the dinghy, something that in some cases you can use to your advantage.

Accelerate with outboard turned to port, towee heads straight.

Accelerate with outboard turned to port, towee heads straight.

After Allez was clear of the slip, I put the dinghy into forward gear, kept the outboard tiller on centerline and gave the outboard a quick shot of power. This stopped the sternway and spun the boat to starboard so that we soon had the boat aimed down the middle of the fairway.

For our first turn to port, I could have turned the outboard into a port turn and accelerated. However, this would have meant fighting the load of the boat being towed to starboard. Therefore, it proved much more effective to turn the towed boat to port by applying a bit of reverse to the outboard. The towed boat’s way then caused her to turn to port as her stern kicked to starboard.

With the outboard in slow reverse, while underway, towee veers to port.

With the outboard in slow reverse, while underway, towee veers to port.

When we got to the final turn and had to maneuver the rig to starboard, I turned the outboard thrust to starboard and accelerated, knowing that the drag of Allez’s 36,000lb meant the rig would turn with very little increase of speed. With just a little practice you too will find you can weave your rig through the marina. With the dinghy on the port hip, it was my plan to bring the boat starboard-side-to at the dock. We, therefore, approached the dock at a crawl. Knowing that as I reversed to slow the rig down the stern would kick to starboard while the bow turned to port (the opposite of forward thrust), I lined things up so that we’d approach at a fairly steep angle on the starboard bow. Ideally, as the rig pivoted, it would stop with Allez parallel to the dock face.

Accelerate forward and the towee turns to starboard. 

Accelerate forward and the towee turns to starboard. 

Unfortunately, as we were entering the final fairway in the marina, George announced that he wanted me to back the boat into a slip so that the finger would be on his port side. That meant I would now not only have to spin Allez around a full 270 degrees to port, but the dinghy could end up trapped between a large steel boat and a dock.

Thinking fast, and with a quick word of explanation to George, I reversed hard, backed to starboard, and Allez slowly responded. Eventually, she also had just enough sternway to back into the slip on her own as the crew cast me off, and I escaped astern.

Slow reverse underway brings bow to port, parallel to dock.

Slow reverse underway brings bow to port, parallel to dock.

The alongside tow may not be an operation you will regularly use, but it is a handy skill to have. It is worth practicing the maneuver before you actually need it—with your boat’s engine running. That gives you a reliable bail-out option. 

This article first appeared in our sister magazine, Sail in the February 2018 issue. While about using a tender to move a sailboat, the same practices can be used to move most powerboats.

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