Sailing Colvic 28 without using motor

[GRAPHICSGEEZER]

Hello-- not sure if this is the right forum. I have a chance to buy a Colvic 28. The owner says he tends not to use it without the motor though the sails are reasonably good. Just wondering, as I'm not familiar with motor sailers, if that's the usual practice. The owner said the propeller is pretty big and would be a significant drag if the motor wasn't providing power. Picture attached shows the size of the prop. Sorry it's so small.

 

[Tranona]

Motor sailers are on a continuum from motor with steadying sails to sailing boats with powerful motors. The Colvic in its standard form is towards the first end - mostly motor but enough sail to be able to sail without motor in a good breeze preferably on the beam. Drag from the propeller is only one of the constraints along with weight, large wetted area, unhydrodynamic keel and inefficient rudder - all obvious from your photo.

Appreciated by those who value comfort, steadiness, space over sailing ability.

 

[Supertramp]

Hello-- not sure if this is the right forum. I have a chance to buy a Colvic 28. The owner says he tends not to use it without the motor though the sails are reasonably good. Just wondering, as I'm not familiar with motor sailers, if that's the usual practice. The owner said the propeller is pretty big and would be a significant drag if the motor wasn't providing power. Picture attached shows the size of the prop. Sorry it's so small.
View attachment 126264

I sail a long keel motorsailer.

Two parts to my answer to your question.

I let my propellor rotate under sail with the engine off (having checked the gearbox is designed for freewheeling). The rotation reduces drag.

I most certainly do turn the engine off and sail. In fact the long keel makes the handling safe and steady. Do not expect to be able to tack up narrow channels into the wind, and expect to travel a little slower than comparable cruisers (with or without a rotating propellor). But close reaching or reaching I can sail as fast as I motor (5-6 knts). You have to learn what the boat will do and what it won't and which wind direction and strength are needed. Same as for most boats.

The motoring performance with a large propellor and engine plus the comfort of a wheelhouse for shelter and navigation provide the upside to the slower sailing performance. I'm not in a rush so the trade off suits me.

 

[Laminar Flow]

We sail the 32' ketch version of the boat you are currently looking at. We have cruised her well over 10.000 miles and in all weather.

Generally speaking, a motorsailer has a sail area/displacement ratio of between 8 and 13; 8 and below is a motorboat with steadying sail and above 13 you are heading towards sailing boat territory.
The Watson 28 has a SA/D of 11.3, one of the highest in the CW range. By comparison, the standard 32 has a ratio of 8.6
I should say the 28 is one of the better sailers of the family.

How do they sail?
With the standard SA/rig you can expect to start sailing in a F3, at the upper end of a F5 you should start to be approaching hull speed. As is, she should be able to do about 50 degr. to windward.

If the gear box allows (check with manufacturer) you can let the prop spin while sailing, at which point resistance is reduced by 40% and the loss in speed would be modest.

There are a few performance issues with the CWs, some of which can be fairly easily resolved, others require a bit more effort.

1). The rudder is too small and inefficient for a sailing vessel. This is compounded by the wide and blunt deadwood (end of keel). Steering problems and refusal to tack under sail are legend with these boats. When pushed, even in moderate conditions, the flat steel plate rudder will stall out, leaving the boat without steerage. As designed they will not back up worth a damn, never mind steer in reverse. Maneuvering in port can be interesting, to say the least.

2). As designed these boats have pronounced weather helm, part of this is caused by the ineffective rudder/deadwood combination, part of it by an unbalanced sail plan. While I have not done the calculations for the 28, I have done these for the 26 and the 32, the latter of which I have considerable experience with - neither of them are balanced.

3). They could do with more sail; quite a bit more, actually.


All of point 1) and a large portion of point 2) can be fixed by slightly enlarging the rudder and giving it a streamlined shape as well as fairing in the blunt deadwood. This is a relatively cheap & easy fix.
In return you get a boat that will tack reliably, steers well in all conditions, backs up in a straight line and steers in reverse. Performance under sail and power will be significantly improved. The drag caused by the blunt deadwood is equivalent to a fixed three blade prop, the flat rudder at 10degr. incidence will cause a drop in speed of 1kt at 6 kts over a profiled form.

Point 3): The Watson has actually, and compared to other motorsailers, quite a stiff hull form with a good hard turn to the bilge and as such is quite capable of carrying more sail. This is most easily accomplished by adding a bowsprit. Ours is designed to fold up and a sprit will also address the problem of excessive weather helm. Our boat had already a taller main mast and longer main and mizzen booms and I effectively doubled her sail area giving us a SA/D of 18.
In 8kts true we reach 5.8kts at 60 degr and in 16 kts (F4) we are doing hull speed. Close hauled we can do 4.8 kts at 40 degr. in 8kts true. We start to reef at about 22kts.

Other than dead to windward her sailing ability is on par with any other displacement cruiser of her length and we have surprised a few supposedly faster boats with sustained speeds of 7.5kts and more. We have averaged 6kts over 210 miles and 6.8kts over 70 miles.

We love he wheelhouse and she is remarkably seaworthy, comfortable and the driest boat I've ever sailed on (including ones that were considerably larger). Additionally, they come with a large engine capable of getting you out of trouble in the worst of weather.

If you are further interested feel free to PM me.

 

[Neeves]

I think if you asked and receive honest answers you would find that many sailing yachts with auxiliary engines spend a lot of their time motoring (without any intent to raise the sails). I think you will also find, if you asked the question and received honest answers, that many yachts don't actually travel very far (and this includes some liveaboards).

I see them leaving on Friday afternoon motoring at near maximum revs and I see them returning on Sunday - and they have spent the weekend on a courtesy mooring - nothing wrong this any of this - but just because you have a 'sailing yacht' or a 'motor sailor' does not mean you cannot use it as you want and best suits its abilities. Its not a competition.

Laminar can obviously help you change the rules.

Jonathan

 

[Wing Mark]

Hello-- not sure if this is the right forum. I have a chance to buy a Colvic 28. The owner says he tends not to use it without the motor though the sails are reasonably good. Just wondering, as I'm not familiar with motor sailers, if that's the usual practice. The owner said the propeller is pretty big and would be a significant drag if the motor wasn't providing power. Picture attached shows the size of the prop. Sorry it's so small.
View attachment 126264

That type of boat is not great up wind.
Neither is it as easy to tack quickly as a fin keeled boat.
Its sails are likely small for its size, because it's not a boat intended for people reluctant to use the motor in light weather.

It's a boat for people who are happy to use the motor when conditions are not ideal for easy sailing.
Maybe it's for people who decide they want to go to a certain harbour on Saturday, and don't want the wind to change their plans.
It's not what I want but lots of people with fin keel raced-derived cruisers seem to have attitudes more in line with this kind of boat.
I've sailed similar and found it frustrating and unresponsive to sail. Not an easy boat to sail well. Slow!

Comes into its own when motoring in the rain, when some of us are thinking 'let's go tomorrow instead'?

It's sort of one end of the spectrum, you can get different balances between wheelhouse weather protection and sailing performance.

 

[Caer Urfa]

Having owned and a Colvic Watson 28'-6" in the past for over 8 years and a CW 23'-6" for over 18 years and a surveyor specializing in Colvic Watsons for the last 16 years from what you say I think the seller sounds as if he has never or hardly ever actually sailed the boat and just used the engine.

In reference to the propeller size and from you photo it does not look over sized to me and propellers on a CW 28'-6" generally range from 370 to 400 mm dia.

You do not say which engine and gearbox is fitted but if possible put the boat in neutral and let the prop spin when under-sail only, again from your photo she looks sloop rigged, like all boats they have their pluses and minus points, CW's do not tack easily and plan ahead and get at least a few knots headway first.

As Andrew comments CW's are famous for there steering (but there's a lot worse) but like everything else you get to know what you can and cannot do and how to handle them , they sail best with a F5 wind and if your going to be in heavy weather then your in one of the safest boats you can buy

I also wrote the History of the Colvic Watson if you would like a copy which will also help you
If I can help further send PM

Mike

 

[fredrussell]

We sail the 32' ketch version of the boat you are currently looking at. We have cruised her well over 10.000 miles and in all weather.

Generally speaking, a motorsailer has a sail area/displacement ratio of between 8 and 13; 8 and below is a motorboat with steadying sail and above 13 you are heading towards sailing boat territory.
The Watson 28 has a SA/D of 11.3, one of the highest in the CW range. By comparison, the standard 32 has a ratio of 8.6
I should say the 28 is one of the better sailers of the family.

How do they sail?
With the standard SA/rig you can expect to start sailing in a F3, at the upper end of a F5 you should start to be approaching hull speed. As is, she should be able to do about 50 degr. to windward.

If the gear box allows (check with manufacturer) you can let the prop spin while sailing, at which point resistance is reduced by 40% and the loss in speed would be modest.

There are a few performance issues with the CWs, some of which can be fairly easily resolved, others require a bit more effort.

1). The rudder is too small and inefficient for a sailing vessel. This is compounded by the wide and blunt deadwood (end of keel). Steering problems and refusal to tack under sail are legend with these boats. When pushed, even in moderate conditions, the flat steel plate rudder will stall out, leaving the boat without steerage. As designed they will not back up worth a damn, never mind steer in reverse. Maneuvering in port can be interesting, to say the least.

2). As designed these boats have pronounced weather helm, part of this is caused by the ineffective rudder/deadwood combination, part of it by an unbalanced sail plan. While I have not done the calculations for the 28, I have done these for the 26 and the 32, the latter of which I have considerable experience with - neither of them are balanced.

3). They could do with more sail; quite a bit more, actually.


All of point 1) and a large portion of point 2) can be fixed by slightly enlarging the rudder and giving it a streamlined shape as well as fairing in the blunt deadwood. This is a relatively cheap & easy fix.
In return you get a boat that will tack reliably, steers well in all conditions, backs up in a straight line and steers in reverse. Performance under sail and power will be significantly improved. The drag caused by the blunt deadwood is equivalent to a fixed three blade prop, the flat rudder at 10degr. incidence will cause a drop in speed of 1kt at 6 kts over a profiled form.

Point 3): The Watson has actually, and compared to other motorsailers, quite a stiff hull form with a good hard turn to the bilge and as such is quite capable of carrying more sail. This is most easily accomplished by adding a bowsprit. Ours is designed to fold up and a sprit will also address the problem of excessive weather helm. Our boat had already a taller main mast and longer main and mizzen booms and I effectively doubled her sail area giving us a SA/D of 18.
In 8kts true we reach 5.8kts at 60 degr and in 16 kts (F4) we are doing hull speed. Close hauled we can do 4.8 kts at 40 degr. in 8kts true. We start to reef at about 22kts.

Other than dead to windward her sailing ability is on par with any other displacement cruiser of her length and we have surprised a few supposedly faster boats with sustained speeds of 7.5kts and more. We have averaged 6kts over 210 miles and 6.8kts over 70 miles.

We love he wheelhouse and she is remarkably seaworthy, comfortable and the driest boat I've ever sailed on (including ones that were considerably larger). Additionally, they come with a large engine capable of getting you out of trouble in the worst of weather.

If you are further interested feel free to PM me.

That’s all well and good but I doubt the OP is likely to want she’ll out the, what, £20k(?) to double sail area and change shape of deadwood and rudder? Far better surely to source a motor-sailer that is more sailer than motor to start with.

 

[rotrax]

Far better surely to source a motor-sailer that is more sailer than motor to start with.

And one of those might be?

Laminar Flow has already stated the Watson 28 is towards the better end of Colvic Watson SA/D.

Our Motorsailer has 14.1 SA/D, still only sails well in ideal conditions. I have just installed my version of the OE option furling reacher, a lightweight 175% foresail.

I was lucky in sourcing a used furler and a new winch at very sensible money and was able to install the deck hardware myself, otherwise it might have been double. Pete Sanders measured up and did the sail. It cost about £4250.00 all in.

Few true Motorsailers sail well in light winds or to windward.

If there is one, please let us know what it is..................................

 

[Laminar Flow]

That’s all well and good but I doubt the OP is likely to want she’ll out the, what, £20k(?) to double sail area and change shape of deadwood and rudder? Far better surely to source a motor-sailer that is more sailer than motor to start with.

To modify the rudder and the deadwood should set you back no more than £500. That's being more than generous and there are even cheaper options.
It is the single biggest and most effective improvement one can make to the brand.

I'm not sure how you arrive at 20 k (sterling no less), that is nowhere near what I spent on our upgrades including a new engine and doubling my sail area cost me less than Rotrax spent on his drifter , including a whole new sail wardrobe, bowsprit and rigging.

 

[Caer Urfa]

That’s all well and good but I doubt the OP is likely to want she’ll out the, what, £20k(?) to double sail area and change shape of deadwood and rudder? Far better surely to source a motor-sailer that is more sailer than motor to start with.

I doubt very much if you have sailed a Colvic Watson from what you say and nobody is suggesting if the OP buys the boat he needs to immediately spend any money in changing sails and making modifications to the deadwood or rudder designs as that's for him to decide as time goes on as there are thousands of Colvic Watson's that sail quite happily without the engine running.
If you want to sail faster and are happy to get soaked in heavy weather buy a yacht

 

[Laminar Flow]

As Andrew comments CW's are famous for there steering (but there's a lot worse) but like everything else you get to know what you can and cannot do and how to handle them

I'm not at all certain that there are worse, presuming it has a rudder at all, and I've sailed quite a few different boats and designed some as well, with the possible exception of the square rigged inner tube I put together as a kid.
I know of no other design, built in series, to which owners have made as many modifications to it's rudder than a Watson and I'm very much of the "if it ain't broke don't fix it crowd".
A boat that needs to be traveling at 30 - 40% of it's nominal top speed to tack is a dud; some owners have told me they need to keep their engine running to effect coming about under sail, really? Some say they have trouble steering a straight course going down wind or that the auto pilot is not capable of coping with the boat's erratic steering behaviour.

The really annoying part is that it can be quite easily fixed and at a very reasonable cost. The few owners that have made the changes have all been able to confirm this.

Any claims that a Watson cannot be made to sail without engine assistance are rubbish, just as any assertion that improving their speed leads to discomfort or, as has indeed been suggested by the same parties, to instant drowning. Quite the opposite, actually.
Increasing the size of the rig and sail area not only makes these boats faster and more pleasurable to sail in condition that do not lead to sudden sphincter failure, but due to increased moment of inertia are more comfortable under way and at anchor.
A boat that cannot sail satisfactorily in conditions when it is pleasant to do so, no matter how incredibly seaworthy it supposedly is, is not really suitable as a pleasure craft.
The idea that light weather performance, sailing ability, seaworthiness and comfort are incompatible is simply not true and a boat that doesn't steer reliably and in all conditions isn't seaworthy either.

 

[penfold]

To modify the rudder and the deadwood should set you back no more than £500. That's being more than generous and there are even cheaper options.
It is the single biggest and most effective improvement one can make to the brand.

I'm not sure how you arrive at 20 k (sterling no less), that is nowhere near what I spent on our upgrades including a new engine and doubling my sail area cost me less than Rotrax spent on his drifter , including a whole new sail wardrobe, bowsprit and rigging.

Is there a thread detailing what you did, particularly to the rudder and deadwood?

 

[GRAPHICSGEEZER]

Just want to say thanks for all your replies so far! Does anyone know how to go about modifying the rudder and keel as suggested here? Can I do this on my own with reasonable carpentry skills? If so, is there a guide for this?

Thanks again

 

[doug748]

Huge boat when seen in the flesh. As the others have said, has a load of advantages, though sprightly sailing will never be one of them.

I would take her for what she is before starting to consider radical surgery which may be no help at all. You can end up with a dog, with the added handicap of being a non standard dog.

.

 

[Laminar Flow]

Is there a thread detailing what you did, particularly to the rudder and deadwood?

There is not a thread per se, but I have mentioned it before and there is an article I had published in the June '20 PBO magazine.

Before: with 5-7" wide deadwood


After

 

[Laminar Flow]

Just want to say thanks for all your replies so far! Does anyone know how to go about modifying the rudder and keel as suggested here? Can I do this on my own with reasonable carpentry skills? If so, is there a guide for this?

Thanks again

Yes absolutely, it hardly requires particular skill. Some have done the dead wood quite rudimentary in foam with glass over and same for the rudder - it had much the same effect. I know someone who ordered the foam cut to a NACA foil section in two halves for the rudder from a company that CNC cuts model airplane wings - rather clever really.

 

[Laminar Flow]

Huge boat when seen in the flesh. As the others have said, has a load of advantages, though sprightly sailing will never be one of them.

I would take her for what she is before starting to consider radical surgery which may be no help at all. You can end up with a dog, with the added handicap of being a non standard dog.

.

By all means try her out as is first, though there is very little that is radical about the improvements I'm suggesting.

Many CWs were home completed and there are plenty of them with really weird ideas and some are grossly overweight and will never perform, no matter what you do to them.
The DWL for the 32' is at the top of the knuckle where the rudder shaft enters the hull. The 32' is the only one, AFAIK, for which the lines were ever published, but I assume it would be similar for the other models as well. If that is not your line of flotation add 500kg of displacement per inch for the 32' and about 400kg for the 28". 20% overweight when fully loaded is normal, more is not.

If my boat is a dog, she is a grey hound compared to her sisters or, as our Dutch sailing friend calls her, a wolf in sheep skin (its why we invite him for Christmas and ply him with food & drink),

 

[fredrussell]

To modify the rudder and the deadwood should set you back no more than £500. That's being more than generous and there are even cheaper options.
It is the single biggest and most effective improvement one can make to the brand.

I'm not sure how you arrive at 20 k (sterling no less), that is nowhere near what I spent on our upgrades including a new engine and doubling my sail area cost me less than Rotrax spent on his drifter , including a whole new sail wardrobe, bowsprit and rigging.

I was plucking a figure out of the air really (hence the question mark) but I was basing it on a new set of sails and a new mast/boom for bigger sails. I doubt you’d see a lot of change from £20k for that lot new. I seem to recall you saying you installed a new mast on yours, no?
And you assume OP has the know-how to reshape deadwood and rudder. To have that done by a person with the skills to do so would cost way in excess of £500.

 

[fredrussell]

…Few true Motorsailers sail well in light winds or to windward.

If there is one, please let us know what it is..................................

How about an LM 28?