Vancouver 28 vs 32 handling

[Laminar Flow]

On long keel vessels the leading part of the entire hull, not just the keel, is part of the lift generating surface.
Cutting a ruddy big hole through it for a bow thruster doesn't really make any hydrodynamic sense.

I still struggle with the speed versus cost benefit of a feathering/folding prop on a relatively heavy boat. The math of relative resistance values doesn't really add up, compared to simply letting the prop mill along for an instant 40% reduction, providing the gearbox allows for this.
The greatest benefit for a feathering prop is to be had on relatively light boats at lower speeds. On heavy boats the resistance at relative speeds over 1 rises so dramatically, not to say exponentially, that any advantage of a feathering prop becomes miniscule.
I have calculated the potential speed gain to be, at best, in the neighbourhood of 0.2 kn, for our 8 and-a-bit ton boat.

Of course, there may well be other speed enhancing benefits to be had from a feathering prop, such as helping to cure endemic weatherhelm, by improving flow over the rudder and thus reducing rudder angles, but for straight up, relative resistance reduction the math is a little fuzzy for a heavy boat.
For my money, adding some light, coloured sail is by far the better investment. In light going, we can easily gain another 1.5 to 2 kn by raising the asymmetric. Now doing 5-5.5 kn, instead of just 3.5 kn, really puts the dent into your passage times.

 

[Babylon]

Darglow Featherstream on my V27 increases light-winds boat-speed by a third of a knot or a bit more with a clean bottom (less with a foul one).

As to the twit who fitted a bow-thruster to their V27...

 

[geem]

As to the twit who fitted a bow-thruster to their V27...

I have been giving some basic lessons to a young French couple this afternoon in the marina at Tasacorte, La Palma. They have a newly purchased Morgan Out Island. A heavy 41ft ketch rigged long keel boat with no bow thruster, dating from the early 70s. Fortunately, there was hardly any breeze. Their marina berth is super tight as it was another €1000 to be on the next side berth up. They are jammed against a wide arse Beneteau next to them, squashing the fenders in both boats.
The prop walk was the wrong way for an easy manoeuvre out of the berth so we had to reverse along the fairway into the main channel. It was about 5 backward and forward shuffles to get us going where we needed to go.

We then did a few trips around the outer harbour letting them get a feel for the boat then I got them both coming alongside the fuel pontoon as its Sunday and it's closed. That went well but we all agreed it was my problem to get it back in the berth! We got back into the tight berth with a bit of fender squashing but no impacts.

It was a great reminder of how hard a long keel boat can be to manouvre. It's about 20 years since I last did it but prop walk is your friend.

These boats pre-date marinas!

 

[Chiara’s slave]

Quite so, people lumber small boats with all sort of hopeless stuff like gantries on the back, furling mainsails, excessive canvass work and then end up motoring about unless conditions are perfect.

Obviously, there’s nothing on our boat apart from that which is essential to sailing, eating or sleeping. Whilst ours is extreme, as cruisers go, every boat benefits from a degree of the same philosophy. It doesn’t take much speed improvement to knock a day off your Atlantic crossing. And who doesn’t want to arrive at a tropical beach a bit sooner?

 

[geem]

Obviously, there’s nothing on our boat apart from that which is essential to sailing, eating or sleeping. Whilst ours is extreme, as cruisers go, every boat benefits from a degree of the same philosophy. It doesn’t take much speed improvement to knock a day off your Atlantic crossing. And who doesn’t want to arrive at a tropical beach a bit sooner?

I guess if we were to empty a couple of tonnes off our boat we may arrive a day earlier but since we have been doing this full-time cruising thing since 2014, an extra day on a long passage is not big deal. We would miss our 5 kites, 2 kite boards, pair of Brompton bikes, wing foil board, two wings, paddleboard, two sets of dive gear, and our 12ft hard dinghy and 15hp engine. What would we do once we got to paradise. We need our toys
If we can't go on the water, under the water or above the water, we would be lost

 

[Wansworth]

Not being an ocean wanderer but considering the months if not years planning to getaway and roamthe world by sail surely the more time spent at sea the better?

 

[Chiara’s slave]

I guess if we were to empty a couple of tonnes off our boat we may arrive a day earlier but since we have been doing this full-time cruising thing since 2014, an extra day on a long passage is not big deal. We would miss our 5 kites, 2 kite boards, pair of Brompton bikes, wing foil board, two wings, paddleboard, two sets of dive gear, and our 12ft hard dinghy and 15hp engine. What would we do once we got to paradise. We need our toys
If we can't go on the water, under the water or above the water, we would be lost

We do take a tender when cruising. Or paddleboards if going to the beach. We have a lot of toys at home, your boat is your permanent home, not like ours which is just another toy.

 

[Tranona]

Darglow Featherstream on my V27 increases light-winds boat-speed by a third of a knot or a bit more with a clean bottom (less with a foul one).

As to the twit who fitted a bow-thruster to their V27...

That is common experience - between 1/3 and half a knot. Flat bottomed boats with exposed props such as on a P bracket or saildrive and where drag from the prop is a higher proportion benefit more. Clearly there are other ways of increasing speed through the water under sail, particularly through more efficient sails, but these are variable depending on how well matched they are to conditions and the skill of the crew in getting the best out of them. The benefit of reducing prop drag is there whatever the crew do or not. In many cases the prop improves motoring performance as some like the Featherstream can be set up with different pitch forward and reverse. When I was more involved with such things I met many owners who reported reduced passage times, for example an hour off a cross channel passage or on longer passages an increase of 10-15 miles in daily runs. The effect of drag from bow thruster tunnels is much more difficult to quantify. On my boat under power it achieves the speeds expected . I have no experience of the boat under sail without the tunnel so can't even guess at the possible loss. All I know is that the combination of better sails, feathering propeller, clean smooth bottom gives speed under sail better than reported by owners of the same class of boat.

 

[geem]

We do take a tender when cruising. Or paddleboards if going to the beach. We have a lot of toys at home, your boat is your permanent home, not like ours which is just another toy.

We still have a house. This is our almost permanent home

 

[dansaskip]

hopeless stuff like gantries on the back,

Far from hopeless, it is a good way to mount solar panels. No need for a generator or to run the engine to charge the batteries. Perfect for ocean crossings and gives independence for shore power when not,

 

[Tranona]

Far from hopeless, it is a good way to mount solar panels. No need for a generator or to run the engine to charge the batteries. Perfect for ocean crossings and gives independence for shore power when not,

But it does have a negative effect on stability and windage, which is the point he was making. That is the trade off for the "free" energy you are harvesting.