Towing A Boat On The Water

If you ever need to tow a boat on the water, this guide will help you be prepared.

Whether the captain failed to perform annual outboard engine service, didn’t know how to judge the tide right and damaged the boat by running aground, or experienced a boat ethanol fuel problem, when a boat needs assistance it’s up to any other boater who encounters them to provide it.

How To Tow A Boat On Water

These days, in many cases that may mean simply placing a call on the VHF radio; it’s fairly simple to arrange for a professional tow boat from either BoatUS or Sea Tow, in most areas of the nation. But in some other situations it may mean hitching up your own boat and towing the disabled vessel back to a port.

In that case, you’ll need to go through all the following steps:

  1. Get a tow line to the disabled vessel
  2. Secure the line to both boats
  3. Set a safe speed and tow the boat to the desired destination
  4. Bring the boat close for the final approach
  5. Release the boat to a pier, mooring, or slip

Getting a Tow Line to the Disabled Vessel

Before you even begin this process, you have to decide what you’ll use for the tow line itself. Few boats haul around a dedicated towing line, and there are some critical points to consider. First, as a general rule of thumb longer is better. You want plenty of distance between the tow boat and the boat being towed, to minimize stress on the tow line. This is especially important in rough water when the tow boat may go up on a wave as the towed boat dips into a trough at the same time, suddenly adding to the tension on the line.

It’s also important to maintain plenty of distance between the boats in case you need to slow down. If the boats are too close together, momentum can carry the disabled boat until it smashes right into the boat that was towing it. As a general rule of thumb, 10 times the boat’s length is considered about right for a tow line. So if you’re towing a 20-footer, 200 feet of line would be a good choice.

Another factor to take into consideration is the type of line and how much stretch it has. Generally speaking, some stretch is a good thing as it can help absorb the changing stresses on the line. So double-braid nylon is considered a good line for towing in most applications. Triple-strand nylon has a bit too much stretch to be ideal, but can also be used.

That said, the truth of the matter is that most of us don’t go cruising around with hundreds of feet of tow line aboard. As a result, out of necessity most of the time an anchor line will be used for towing. Since both boats involved probably have an anchor line aboard, it’s wise to consider these factors when choosing which one to use for the tow.

Towing Between Boats

With the tow line chosen, you’ll now have to get the end of it from one boat to the other. In calm conditions, a good throw should get the job done. Make two sets of coils at the end of the line, and hold one in each hand. As you throw the end-coil with your right hand (assuming you’re a rightie) simultaneously open your left hand, palm up, and fully extend your arm. This will allow the coils in your left hand to fly out, and maximize the distance the end of the rope will travel.

When conditions or line size doesn’t allow for an easy toss of the line from one boat to the other, there are two techniques you can try. First, you can choose a lighter line and tie a throw-able object, like a life ring, to its end.

Once you throw it to the other boat, the light line can be tied to the end of the tow line and then pulled from one boat to the other. This will extend your throwing distance a bit (especially if the tow line is heavy and difficult to toss), but sometimes you still won’t be able to bridge the gap between the boats. In this case, try tying the end of the line to a floating object like an extra lifejacket or a jug. Then you can let out a long distance of line as the boat idles forward, and tow it right past the disabled boat. As long as someone aboard has a boathook or fishing gaff, they should then have no problem snagging the line and pulling it in.

Securing And Tying A Tow Line Between Boats

When towing a boat on the water one of the most important things to remember is that you’ll want the force centered on both vessels, not off to one side or the other. Cleating off the line on a tow boat’s corner transom cleat will make steering incredibly difficult. Similarly, if the bow cleat on the towed boat is off-center you can bet the boat will constantly pull off-course. As a result, it’s important for you to know how to make a tow bridle.

To make a tow bridle, you’ll need a shorter length of line. It should be about twice the tow boat’s beam, and usually, a mooring line will be about right. You’ll want a loop at both ends, so if it doesn’t have them on one or both ends use a bowline knot to add the loop. Then, hold the two loops together and pull the doubled line to its end, which will be in the very center of the line. This will be the tow point, and you can either tie a cat’s paw knot there, or attach the tow line by putting a shackle around the bridle line.

If the tow line you’re working with has a bitter end with no loop nor shackle, you can again tie bowline, but this time tie it around the bridle line. Finally, secure each of the bridle line’s loops to the tow boat’s stern cleats. Now, the force of the tow line will always be pulling against the centerline of the tow boat.

Attaching the line to the towed boat will be simpler if it has a centered bow cleat, as is often the case with relatively small boats. But if the bow cleats are off-center, making a bridle for this boat is in order as well.

Set a Safe Speed for Towing a Boat

Now you’re ready to get underway. But, just what is a safe speed for towing a boat? Unfortunately, there’s no one-size-fits-all answer. It depends on the size of the boats, the state of the sea, the appropriateness of the tow line and gear, and many other factors.

For starters remember that you’ll never be able to get a towed boat onto plane, so don’t even try. Five or six knots is probably a good target and you can’t hope to go more than a knot or two faster, so just try to find a comfortable speed and if the rope or either boat seems stressed, ease off a bit. The bottom line? This is a judgement call.

Towing Tip: If the boat being towed wanders back and forth from port to starboard and it has an outboard or stern drive engine, lower the drive unit until the skeg is submerged and center the wheel to provide some lateral resistance. In the case of an inboard boat, always make sure the wheel is centered.

The Final Approach When Towing a Boat

That long tow line is great for putting miles safely under the keel, but it’s not so great for maneuvering. In fact, you’ll have little ability beyond going in a single direction. So when you approach a marina or pier, it’s time to shorten up the tow line and drop to minimum speed. If possible, you’ll want to eliminate the tow line altogether and begin towing “on the hip”

Towing on the hip essentially means tying the two boats together as tightly as possible, so the powered boat can maneuver both boats at the same time. Start by deploying as many fenders as possible between the two boats (you can use extra life jackets in a pinch) and position the powered boat’s bow about two-thirds of the way forward on the disabled boat.

In all cases, the powered boat’s propeller should be aft of the disabled boat’s transom. Then use multiple lines running fore and aft to both boat’s aft, spring, and bow cleats. As you secure the boats together, wait for them to rock in the waves and take up any slack in the lines that results from rocking and rolling. Getting the boats tied to one another as tightly as possible is key, to minimize motion between the boats and (hopefully) prevent them from banging against each other.

When towing on the hip maintain minimal speeds, but remember that maneuvering will take brief applications of power. If the boat doing the towing is smaller than the boat being towed, the applications of power may need to be significant. In any case expect turns to take lots of additional space.

Releasing a Boat Under Tow

When you’ve reached the end of the tow, it’s important to be prepared. The crew on the boat being towed should be ready with lines, additional fenders, and boathooks prior to reaching the dock, so there’s no last-minute scramble. Once the disabled boat is secured in place, the tow boat can release their lines and get back to having fun out on the water.

Safety Considerations When Towing a Boat

Towing a boat puts a lot of stress on the boat and its gear, and introduces several unique safety concerns everyone needs to be aware of. Before you try towing, make sure these towing safety tips are ingrained in your memory:

Keep passengers away from the tow line, and off to either side of it. If the line snaps or a cleat rips out, it will sling-shot back in a straight line with dangerous velocity. On boats doing the towing the passengers should go to the bow or into a cabin if possible, and stay as far away from the tow point as is reasonable. On boats being towed passenger should stay as far aft as possible, or go into a cabin.

Once you’re under way, adjust the length of the tow line slightly to try to match up the two boats’ motions with the sea conditions. Ideally, you’ll want each to rise and fall on the waves in synch with each other, in order to minimize stress on the lines and attachment points.

At the end of the tow, remember that the restricted visibility and ability to maneuver may make approaching a dock a bit more dangerous than usual. Crew should be instructed to keep hands and feet inside the boat, and never let any body part get between the boat and a solid object when fending. In fact, it’s best to equip the crew members with fenders and instruct them not to use their hands or feet at all to fend the boat.

Set up a communications plan between the two boats before you begin towing. Ideally this means picking a channel on the VHF, but it can also mean trading cell phone numbers or even just establishing basic hand signals for communications like “slow down,” or “stop.”

If you’re captaining the boat that’s doing the towing, be careful not to back over the tow line and tangle it in your prop if stopping or slowing down becomes necessary. Whenever you know the tow line is going to go slack, it’s a good idea to post a crew member at the stern to take up line and make sure it never gets near the propeller.

Err on the side of caution – if you feel anything is unsafe, just call the whole thing off and wait for help from the professionals.

It’s true that the with the widespread availability of professional boat towing operations on the water today, you may go for years without ever having to tow a broken-down boat. But remember, when you do encounter someone who needs help it’s incumbent upon you to render assistance – that’s the law of the sea. Fortunately, armed with the right knowledge you should be able to tow a boat on the water without any problems, and then enjoy the rest of your boating day secure with the knowledge that you’ve done the right thing and helped out a fellow boater.

Written by: Lenny Rudow

With over two decades of experience in marine journalism, Lenny Rudow has contributed to publications including YachtWorld,, Boating Magazine, Marlin Magazine, Boating World, Saltwater Sportsman, Texas Fish & Game, and many others. Lenny is a graduate of the Westlawn School of Yacht Design, and he has won numerous BWI and OWAA writing awards.


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