Towing a big tender

I know some here on TF tow fairly big boats as tenders from time to time. My dad is in his mid 80s and he has given up on using his older 1990 vintage Triton 17' bay boat, so he gave it to me to do whatever with. It has a 115 Hp 2 stroke Yamaha on it that's pretty troublesome. Hard to start, noisy, not very reliable.

The boat itself seems to be in decent shape however, so I was wondering about sticking a newish 4 stroke, smaller engine on it in the 70-90hp range and using it as a tow behind tender if I ever got towards the Bahamas. I'm just not sure how much that would drag down my fairly lightly powered (100 HP Yanmar) cruiser. Seems like a lot of boat to tow but I know others do it, but maybe with bigger boats than mine.

What say you? Is it worth the effort and money, or should I go onto the next idea?

It looks about like this

cardude01 said:

I know some here on TF tow fairly big boats as tenders from time to time. My dad is in his mid 80s and he has given up on using his older 1990 vintage Triton 17' bay boat, so he gave it to me to do whatever with. It has a 115 Hp 2 stroke Yamaha on it that's pretty troublesome. Hard to start, noisy, not very reliable.

The boat itself seems to be in decent shape however, so I was wondering about sticking a newish 4 stroke, smaller engine on it in the 70-90hp range and using it as a tow behind tender if I ever got towards the Bahamas. I'm just not sure how much that would drag down my fairly lightly powered (100 HP Yanmar) cruiser. Seems like a lot of boat to tow but I know others do it, but maybe with bigger boats than mine.

What say you? Is it worth the effort and money, or should I go onto the next idea?

It looks about like this
View attachment 61606

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many boats in my YC tow largish boats behind but that is mainly in protected waters in the PNW and almost all the towing boats are over 45 foot MV or if you like MY types not sail.

I've got no experience in the Bahamas but....
I'd think twice about towing it in unprotected waters.

If the boat is too small to cruise the waters, it is too small to get towed in the same.

Pro fisherman tow multiple dories out and around the great barrier reef and have done forever.

Towing a largish tender to common practice here in South Florida. There is a small industry here that makes the accessories for this specialty market and many FL boat-builders offer a reinforced tow eye option.

You need to make sure it's worth the extra effort, like going to the Bahamas or the Keys where they are invaluable. Also, this is not for the shorthanded cruiser, most put a crewmember on the tender and untie for docking or course quarters.

I think if you are a cruiser that spends time at destinations.....probably a great idea and worth the effort.


If you are always on a light schedule, moving, spending a lot of time at marinas or anchorages where the run is short to the beach or dock....not probably worth it.


I plan on doing it at least one year snowbirding to see how it goes.


A large dingy will make anchoring out the vast majority of the time a lot easier/nicer for getting back and forth and doing "other" things in than just the short, get to town runs.

We have a 15' AB RIB that we tow up to the local anchorage via the ICW. Great for wake boarding and towables and getting around in comfort.

But I would NEVER tow it to the Bahamas. The Stream can be a very unfriendly place.

But then I have a 11' tender on the boat deck with a davit.

There was an article in PassageMaker a while back about a boater having to be rescued after his tow ran down the back of a wave and holed his stern. I'll see if I can find that.

Towing to, from and in the Bahamas is very, very common.

We tow a 34' Grady White.

On another boat I towed a 24' inflatable with a 250hp outboard on the back from Ft. Lauderdale, through the Panama cannal to the west coast of Costa Rica and then back to Fort Lauderdale with no issues.

Capt.Bill11 said:

Towing to, from and in the Bahamas is very, very common.



We tow a 34' Grady White.



On another boat I towed a 24' inflatable with a 250hp outboard on the back from Ft. Lauderdale, through the Panama cannal to the west coast of Costa Rica and then back to Fort Lauderdale with no issues.

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Wow ,34 feet, what size boat are you towing with?

Dang-- towing a 34' Grady. That's big.

How much drag does towing a bigger tender put on the boat? I know it probably depends on the boat that's doing the towing.

I might just get the stupid 115 Yamaha running again and try it out on my boat before I invest the money. I have a feeling it might slow my boat down quite a bit, and my boat is already slow.

Wonder if a big rub rail can be added to a boat?

cardude01 said:

Wonder if a big rub rail can be added to a boat?

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Sure it can, just sell a few extra cars that month.

Found this, if I wanted to put about a thousand screws in the boat.



I sold the car lot so maybe that's why I'm looking for a project. The more I think about it however, it looks like too much work and expense for something I don't need or won't use much.

We have towed a 13', 14' and 15' inflatables with an early 34 Mainship and a 38 Flybridge mostly at lower speeds. After that we towed a number of inflatables between 15' and 24' behind 45 and 47' boats mostly at speeds between 15-18 knots. Maybe near 5,000 miles of towing or more over the 10 or so years we towed at the faster speeds. The towed inflatables had self bailing cockpits , the tow was set back on the second wave and we never had any issues during towing or at ports.
In our case we did not have a slip so the tow often took us out to the boat for each excursion - I think if you plan well it will go well.

johnrupp said:

Wow ,34 feet, what size boat are you towing with?

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82'

On the 100' Broward I used to run we towed a triple OB 43' Intrepid.

I crewed on a 90' MY that cruised at 10-14kts. Sometimes we towed a 35 Contender. The amount of tension in the tow line was unreal. The contender was half planed out, right where drag was highest. I figured the burn rate on the 90 was about 25% higher with the tow. And the 90 was a very sleek full displacement hull shape.

We towed in 10-12' confused seas for one passage, and I figured we would lose the tow. Never did.

The issue with the OP is that your big boat will have a much higher hull speed than the tow, and probably not enough hp and speed to get the tow to "break over" and reduce drag. So the whole rig will be a good bit slower and burn more fuel than alone.

But it should tow pretty safely. At tow speed of say 6kts, bow will be up and should handle most seas. But be aware that bad things happen with tows, and sometimes for no obvious reason. Look back and Whoa??? Where's the tow?? Things like that like to happen at night, too. For some reason. Make sure it has good lighting.

But it is super nice to have a skiff in the islands. Anchor the mothership in a nice spot and go exploring with an easy to handle skiff. It's a huge improvement in the island experience.

Boating buddies with a 32 Nordic Tug have been towing on the Inside Passage for some years. Starting with a 14' Whaler, now an 18' Hewescraft. They wanted a more capable taxi and fishing/exploring boat that could take 4 people comfortably and keep them dry.

Traveling at 7 knots, they found that the longer boat was easier to tow, because the shorter one's hull speed was so much lower that it was trying harder to get up on plane.

I towed my little 10' RIB from Key West to Fort Myers and it was bouncing and bobbing all over the place. I was constantly fiddling with the tow line to try to find the sweet spot. Not sure I ever did.
Now that I think back on it, the tension on that tow line was pretty strong, so strain on a line pulling a 17' skiff would be considerable.

Again, I guess I need to try towing the boat as is to see if I like it before spending the money.

We would almost always tow our 10' rib behind out sailboat as hoisting it on deck was a bit of a hassle. The issue for us is that it made getting in and out of slips much more of a hassle, particularly if we were short handed. Towing when out in a an area where we were anchoring most days was not a problem.

On the flip side of tender towing question, I've done it and don't like it. At every anchorage, marina and fuel dock, you are bringing it up along side and then sending it back out when you leave. Lots of opportunity to get the painter tow line in the big boat's props. Tying up at marinas is a hassle with a tender. Every year I see big tenders being towed to Alaska. If any of the weather choke points get really rough unexpectedly, you are now trying to take care of two boats rather than one and tenders have been lost in this scenario. You would also be surprised at the incremental fuel required to tow. Yes, once you're anchored, having a big tender to fish, dive and explore from would be great, it just isn't worth the downside, IMO.

I guess a lot depends upon where you might be towing and where you might be visiting.
Here in the Northeast (LI sound and areas nearby) towing to most marinas is not a big deal - we call ahead and have had no issues with slips or with spots to put the larger inflatables. These larger self bailing inflatables (16'-24') tend to tow much easier then the shorter ones. With a 47' boat and speeds in the area of 7 knots the fuel consumption was not really measureable. When towing the largest 24' at about #3,500 and at 16-18 knots the fuel use was right around 5% more with the tow in place. On one typical 200 mile trip 'loop' that added about 9 gallons of extra diesel used.

I was really just thinking about the Bahamas. If I did it I think I would trailer it to the FL east coast and pick it up there. I can't imagine pulling something like that all the way from Texas to FL, through the locks and all the tight areas around the barges. That would suck.

Check with your insurance company. A friend last year contacted his insurance company (Geico Marine) about towing his 18.5' Key West behind his 40' MainShip from Florida to the Bahamas. He forwarded the response to me.

Underwriter confirms that there currently is no exclusion for towing the skiff, but that an endorsement will be issued to exclude such use due to the size of the skiff. That means the yacht policy will not provide liability coverage for towing the 18' skiff. I will forward policy change documents to you upon receipt. Emergency towing would not be subject to this exclusion.

Larry M said:

Check with your insurance company. A friend last year contacted his insurance company (Geico Marine) about towing his 18.5' Key West behind his 40' MainShip from Florida to the Bahamas. He forwarded the response to me.

Underwriter confirms that there currently is no exclusion for towing the skiff, but that an endorsement will be issued to exclude such use due to the size of the skiff. That means the yacht policy will not provide liability coverage for towing the 18' skiff. I will forward policy change documents to you upon receipt. Emergency towing would not be subject to this exclusion.

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However, typically one would have insurance on the tender which would cover it so having liability coverage on the main boat wouldn't be an issue.

Most of our trips north, we towed a 20ft Hewescraft. We never had any issues when we would go into a dock we just tied it to the side of the boat and asked for a side tie... The fuel consumption didn't go up but the cruising speed dropped about 10%... It is really nice to have a capable tender to fish, crab and other activities that are a pain to do in the big boat....

BandB said:

However, typically one would have insurance on the tender which would cover it so having liability coverage on the main boat wouldn't be an issue.

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You may be right but our friend's state side coverage wouldn't cover him for the Bahamas.

I cut and pasted what our insurance policy reads for our tender/dinghy. As our friend said "maybe I asked too many questions".

“Dinghy” means a boat not to exceed 14’ length overall, including an outboard motor that does not exceed 40 horsepower, if so equipped. The maximum coverage for any dinghy and its outboard is $15,000. The dinghy must be primarily used as the tender to the insured boat listed on the Declarations Page.

Ka_sea_ta said:

Most of our trips north, we towed a 20ft Hewescraft. We never had any issues when we would go into a dock we just tied it to the side of the boat and asked for a side tie... The fuel consumption didn't go up but the cruising speed dropped about 10%... It is really nice to have a capable tender to fish, crab and other activities that are a pain to do in the big boat....

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That works if there is a side tie available. I have been to lots of places where that is not the case. I also have been to plenty of fuel docks where there isn't really enough room to have a tender tied to the side. (Thinking of Narrows Marina in Day Island or Breakwater at Pt. Defiance when it was still in operation.)

I've towed my 17' c-console several hundred miles on the rivers, through locks and on Lake Michigan. Never had any problems but always had at least 2 people onboard to handle the tow gear when locking.

The previous owner of my monk left fuel use records from towing a BW 13 ft Sport He dropped from over 3nmpg to just over 2 nmpg and avg about 6 kts

Larry M said:

You may be right but our friend's state side coverage wouldn't cover him for the Bahamas.

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Now, as to towing. Guess I'm one of the last holdouts. I don't like the thought or any aspect of it. I know many captains who have done it for years and keep telling us we should do it. We do have RIBS with us so that covers most of our needs. If we feel a need for something larger then we just rent wherever we are. I just have a mental block when it comes to towing long distances under variable conditions.