Towing an inflatable

[skipjack27]

I have a 27' flybridge cruiser with a 200hp Volvo AQD41A engine and Duoprop 290 leg. I'd like to buy an inflatable boat to use as a tender - something that could carry around 4 adults, and be somewhere in the range of 2.5-3.0 m in length. My cruiser is already underpowered (2 engines is more usual for these craft), generally doesn't get up on the plane (unless completely clean and unloaded), and can't cruise at anything more than about 13-14 kts.

I have 2 questions:

1. Would it significantly slow my boat to tow a tender as described above?

2. What is the best way to tow such a tender (i.e., how far behind; in the sink beyond the first stern wave, etc?)

Look forward to any useful hints!

Jeff

 

[smitty477]

Re: Towing an inflatable

Hello Jeff,

I have 2 questions:

1. Would it significantly slow my boat to tow a tender as described above?
A tender of that size will not appeciably 'slow down' you boat and the extra fuel burn with be hard to detect.

2. What is the best way to tow such a tender (i.e., how far behind; in the sink beyond the first stern wave, etc?)

With a "Y" bridle at each end and a good fast attachment device (snap schackle, etc) so that you can deploy and retrieve easily.
The best place to two is after the crest of the second stern wave - its a ways back there.

Look forward to any useful hints!

Questions you have not asked but might help...
Will this be a RIB? (these are much easier to tow)
Will you be towing with engine and gear onboard?
Will you tow in wind/rain/fog/night conditions?
What happens in unexpected rough weather?
Will you be using a floating line and/or floats?

We have happily towed various inflatables for well over 5,000 miles now at cruisig speeds but it does take a bit of planning ahead of time to have funb.

Hope this helps

 

[TOHATSU GURU]

Re: Towing an inflatable

You would never tow any inflatable above 7 or 8 mph as none of them, RIB or soft bottom, are designed to be towed at the speed you are contemplating. Many people do tow at higher speed, but those people are the ones's who loose and damage their dinghies.

 

[smitty477]

Re: Towing an inflatable

"Many people do tow at higher speed, but those people are the ones's who loose and damage their dinghies.'

This may be accurate for some folks dependent upon what they are attempting to do and where.
Depends on where the OP is and what he wants to tow (size and type) and in what conditions.
Perhaps the OP wants to tow across a sheltered area for day trips only - cant really tell from the information so far.
That is one reason to add the additional questions to see if we can add some helpfull ideas and/or insights
We have had a number of ribs that towed well at speed for long distances and were in exellent shape.
Likely the ones we have now are in better shape than most any that are out there.

Hope this helps

 

[TOHATSU GURU]

Re: Towing an inflatable

My comments were not directed at you Smitty. I've been selling, servicing and operating inflatables since 1988 and tend to see the worse possible result of people's usage However, what I said is a generalized statement and there are always exceptions where people have been lucky enough not to experience pussastrophic failure as a result of misuse. If someone insists on towing an inflatable at 20 mph and doesn't have a problem...More power to them. But the fact remains that they shouldn't.

 

[smitty477]

Re: Towing an inflatable

I can guess that boating activities and typical methods vary widely dependent upon what area the person boats out of. I can easily say I know nothing about boating out of the Tampa area and likely could be misled by practices within that area.
Around where we have boated these past 25 years the area is ‘protected’ by being in Long Island Sound (NY) and further protected by close groups of harbors which favor’s shelter. Within these areas many boaters ‘moor’ there boats rather than having them at a slip as the practice is quite safe and affords a lot of area for boats. Additionally a large practice of this smaller dinghy towing occurs on the lager fresh water rivers and lakes around here such as the Hudson and the Ct. river area.
It is quite common to have boaters utilize inflatable dinghies to gain access to their larger moored boat. It is also quite common to them bring that dinghy along which in many cases means towing it to a nearby (2-6 miles) anchoring areas within these protected harbors. Although some of us do tow for much longer distances in more open waters that is usually relegated to the larger inflatables above 15’ or so. It is typical to see dozens of smaller dinghies with and without motors attached moving to these anchorages for raft ups each week year after year with no incidence as long as they have planned their tasks. We have actually towed various inflatable but would suggest that RIBS are far easier to move over short protected distance without too many preparations – that was the purpose of my questions back to the OP.
Over the past 10 years or so about a half dozen of us have towed larger inflatable’s over many thousands of miles with no issues using some preparations ahead of time. This ability has certainly allowed us to enjoy many parts of boating that would be impossible without these RIB support boats. (Sea Doo explorer, Zodiac, Nautica , AB, etc)
I do agree and can easily see how someone could make a mess of towing and end up in an unsafe/unwelcome position and that another reason why I posted some of those questions back.
Since I have no real idea how the OP was going to approach this I would say we need much more information from him. I do know that he likely has an unusual set of circumstances as a quick search of his posts leads me to believe he is in Australia and boats with a single diesel large prop primary boat. So it is possible he is in a large protected area or maybe he heads to unprotected waters but that set-up would tend to tow quite well if he has sheltered areas all of the time.
Hope this helps

 

[Sea Rider]

Re: Towing an inflatable

Some tips.

1-If using a towing Y bridle, bridle must have a float where Y matches straight line to avoid prop entanglements with line.
2-Sib/rib must be towed without passengers inside

For portable engines only
3-Raise engine out of the water and turn leg to a side.
4-Secure a small line between both clamp eyes, independently of any other form of attaching a rope to engine body.

Some boasters doesn't tie any rope to engine to find out after towing that engine is missing, very bad music. If you do secure a rope but don't tie both clamp's eyes, be aware that if clamps become lose while towing you could have engine travelling along under hull at rope's lenght...

Happy Boating

 

[smitty477]

Re: Towing an inflatable

Sea Rider,

"1-If using a towing Y briddle, bridle must have a float where Y matches straight line to avoid prop entanglements with line.
2-Sib/rib must be towed without passengers inside

For portables engines only
3-Raise engine out of the water and turn to a side.
4-Secure a small line between both clamp eyes, independently of any other form of attaching a rope to engine body."

All good points you have posted...
Besides floats on the tow line we also utilize line that floats by itself. That coupled with well placed chafe guard allows for the bridle to be easier to use and have a very long life.

Hope this helps

 

[skipjack27]

Re: Towing an inflatable

Many thanks for the considered replies to my query. Serious food for thought.

In answer to some questions: I boat in Perth, Western Australia, and would be towing the inflatable out to one of the islands around 12 miles off the coast. My rule is to avoid boating in seas of more than about 5 feet, but Perth is where the US lost the America's Cup for the first time in around a 100 years or so. That's because of our horrendous sea "breeze" that can scream in at anything up to 30 kts on an ordinary summers day. Our crew were used to it; the US crew weren't. So, the sea height can be a bit uncertain...

I'm concerned, though, about the apparent limitations on towing speed. I can certainly appreciate that roll-ups can't be satisfactorily towed at speed, but I'm rather surprised that RIBs aren't more capable in this regard.

Is it really not advisable to tow an RIB at speeds of around 12 kts? I'm thinking here of a modest RIB of around 2.5-3 metres.

 

[Sea Rider]

Re: Towing an inflatable

In flat calm or slight choppy waters it's possible, not sure about rough and extreme windy waters, try it without the engine and see what happens...the worst, will have a flipped small rib which by the way is unsinkable. A rib tows much better than a sib, hull rigidity issues.

Happy Boating

 

[smitty477]

Re: Towing an inflatable

A 10' rib in 5" seas with up to 30 knots wind potential I am now going to agree with Tohatsu Guru and say - don't do it.
There is not a suitable bridle nor method to safely tow that size/weight boat with the larger seas and winds you have described.
That is also actually on the edge of the conditions we would tow 19-24' Ribs with much heavier/stable footprints.
If you want to seek many more opinions from folks that see this much more than post over at 'Ribnet' and see what might come back.

Safe boating and hope this helps

 

[KrisKastel]

Re: Towing an inflatable

Ive had some experience in towing and inflatable, and if it is not a RIB, and just a PVC inflatable keel type, i wouldnt tow them too fast. The D rings are only glued on most the time, so they are not made for towing at all. Also the towing force can stretch out your tubes, and cause damage to the rest of your inflatable too.

So if its a RIB its ok, but otherwise not.

 

[Nos4r2]

Re: Towing an inflatable

Try putting it on snap davits.