Towing Inflatable - Optimum Painter Length?

[emsworthy]

Looking ahead to a summer of short cruises where we often want to tow our 2.7m inflatable tender, got me thinking about what length of painter is the optimum to minimise drag. I've tried it with the bow hauled up tight high on the transom with just the two pointy bits in the water and also on a longer line sitting/surfing in the back of the wake, but still not sure if either is right.

Any thoughts? The boat is a modest Sadler 26 so not an option for davits or storing on deck/locker really. Towing is the only way if we want it with us.

TIA.

 

[stuarta]

My brother and I have stored a small inflatable fwd of the mast on a Sadler 26 - it needs to be put in the water before any mooring/anchoring activity but it sits there quite happily on passage without fouling the genoa at all. When towing we need to vary the painter length depending on boat speed and conditions. It is generally happier with the bow raised a little - it is a soft floor round-tail. I think trial and error and then perhaps mark the painter with the length that suits to make it easier next time round.

My Sadler 34 has the babystay in the fwd position (on foredeck rather than coachroof) which means I have less room for a tender up there than we do on the 26!

 

[Ripster]

We played about with this last season and found for us (36ftr) about 15-20 feet worked best just aft of any rudder or stern wash with a short bridle at the dinghy end to make the tow central on it and attached to one of the main aft cleats to one side. On a our longer runs at sea (as opposed to just moving up a river or something) I also rigged up a 2nd light line just for security and in case the waves built up. Towing loses us about half a knot in sailing speed too.

 

[johnalison]

I have found, or thought I've found, that pulling the dinghy, an Avon Redstart, close up with the bow clear of the water produces the best effect. I don't really like towing a dinghy, but occasionally do between West Country ports. My judgement is based on the amount of pull when the painter is held in the hand.

 

[Tranona]

There isn't an optimum, but the two options already suggested are the most common. As always, pros and cons. Long painter keeps it clear of the stern and it can make its own way over waves etc, but probably best in gentler conditions as always the risk of it either filling with water or flipping. Pulled up tight probably creates more drag, but the dinghy becomes more part of the boat. Needs securing well so it does not bash around. Probably better with roundtails than solid transom.

 

[johnalison]

. Pulled up tight probably creates more drag, but the dinghy becomes more part of the boat. Needs securing well so it does not bash around. Probably better with roundtails than solid transom.

This may be the case with some boats but if I am trailing my dinghy at motoring speed there is a very strong pull on the painter if I try to draw it in, which lessens markedly as soon as the bow of the dinghy leaves the surface.

 

[Cloven]

Anyone tried towing a dinghy, hard transom type, with the stern pulled tight up to the pushpit and just the bow in the water? Seems to me that eye bolts in the transom are inherantly much stronger than glued on fittings on the bow.

 

[PeterR]

When chartering with heavy RIB type dinghies we found it paid to heave them in tight and lift the bow out of the water. In my own boat we found with a lighter dinghy and a reasonable boat speed it paid to tune the length of the painter to get the dinghy running downhill on the front of the sternwave. Compared with pulling it uphill on the back of the sternwave we gained .2 to .3 of a knot.

 

[jerrytug]

Anyone tried towing a dinghy, hard transom type, with the stern pulled tight up to the pushpit and just the bow in the water? Seems to me that eye bolts in the transom are inherantly much stronger than glued on fittings on the bow.

Yes it worked well.

Having any of the tender's weight supported by the yacht transom can only reduce the drag, and the hard dinghy transom is heavy.

 

[dylanwinter]

Anyone tried towing a dinghy, hard transom type, with the stern pulled tight up to the pushpit and just the bow in the water? Seems to me that eye bolts in the transom are inherantly much stronger than glued on fittings on the bow.

someone somewhere should make a film about it

https://www.youtube.com/watch?v=sa5CVt_hGMk

D

 

[LONG_KEELER]

. In my own boat we found with a lighter dinghy and a reasonable boat speed it paid to tune the length of the painter to get the dinghy running downhill on the front of the sternwave. Compared with pulling it uphill on the back of the sternwave we gained .2 to .3 of a knot.

+1 on the above.

Thanks for the tip Dylan. Will definitely give it a go . Apart from the other advantages, the dinghy's transom close to the mother ship could also take advantage of falling on the stern wave in the right conditions.

 

[Cloven]

someone somewhere should make a film about it

https://www.youtube.com/watch?v=sa5CVt_hGMk

D

Thanks for that Dylan. Answers my question particularly as that's exactly how I attach the dinghy to the boat when transferring from boat to dinghy and also gives much greater stability when lifting the outboard from the pushpit onto the dinghy transom. I have a small boarding platform on the boat transom so with one foot on that and one in the dinghy I can easily do the outboard transfer.

 

[MM5AHO]

Another issue to consider is engine cooling water if towing under power.
We have to have either right up tight against the stern, or well back. Otherwise the dinghy fills with exhaust water. (stern exhaust, would not apply if a side mounted exhaust)

 

[capnsensible]

Towing a dinghy usually ends, eventually, in tears. That's probably why so few people do it these days.

All it takes is a bit extra effort. I'm not alone in having to force myself not to be lazy!

 

[Ruffles]

Towing a dinghy usually ends, eventually, in tears. That's probably why so few people do it these days.

All it takes is a bit extra effort. I'm not alone in having to force myself not to be lazy!

I sort of agree. Though I almost always tow a hard dinghy - sometimes two!

Many occasions I've had to bail out the dinghy in a swell with one foot on the yot and one in the dinghy. Not terribly safe particularly when single handed. On another trip back from Poole I had a following sea that threatened to put the dinghy through the transom. I now have a very old stretchy climbing rope that seems to help.

 

[Poignard]

someone somewhere should make a film about it

https://www.youtube.com/watch?v=sa5CVt_hGMk

D

Here's another useful tip:

To save splintering one's nice varnished transom, clamp a piece of scrap wood to it and drill through into that.

 

[Jaguar 25]

Any merit in attaching the dinghy to the side of the boat?

In a marina I would do this to save hauling it on board. Seems it would be possible to sail with the dinghy on the side attached to the guard rails with one side in the water.

 

[Billjratt]

I have davits now, but previously towed various dinghies - all had a wooden transom so a bridle was fitted between the quarter eyebolts and attached to the painter above the bow (leaving slackish line to the bow eye). This applied the towing pressure to the back like an outboard, stabilising the dinghy which is now able to plane if it needs to. Another advantage is stability when the parent boat is at anchor - if there's a gale it won't flip or try to fly round the mast.

 

[VicS]

Any merit in attaching the dinghy to the side of the boat?

In a marina I would do this to save hauling it on board. Seems it would be possible to sail with the dinghy on the side attached to the guard rails with one side in the water.

We use to do this with an Avon Redstart on a Westerly Berwick.

Preferable to carry on the windward side to give additional shelter to the cockpit and to keep it out of the water.

When cruising along the coast we preferred to put it on the seaward side so that while there was some coastline to view we could see it.

When no other reason to choose one side in preference to the other we carried it on the starboard side as the inflation valves were not then bashing against the side of the boat.

We often wondered why nobody else carried their dinghy like this

 

[Spyro]

I suppose it all comes down to how much drag is produced. I reckon a set of handheld luggage scales between the towing point on the towing boat and the painter on the dinghy would give fairly accurate results. Sounds like something PBO should have covered. I only ever tow short distance and in a flat calm otherwise it's upturned on the foredeck or hauled up on the transom sittting on the boarding ladder.