Bestevaer 49 vs Orion 49 - which is the better aluminum pilothouse?

[Dockhead]

Originally Posted by Walawala11

Manateeman, I had not really considered twin keels. It's not something I see very often. I'm trying to keep things relatively simple, so I was planning on a fin keel. I will investigate further. Thanks.

Twin keels are really great for coastal cruising in tidal waters. Dry out without any faff, don't worry about going aground (provided suitable weather), save a lot of money on haulouts. Very popular around the English Channel and English East Coast. Downside is relatively poor upwind performance.

[Manateeman]

WOW. The comments on twin keels. I guess I’ve got to go back to Ted Brewer and get a refund.
Let’s see. Two old guys. One has been building yachts for half a century and the other who has been designing yachts for half a century. What would they know?
Dear original poster.
You are having a vessel built for you. May I suggest following the suggestions of professionals. It’s nice to see the range of opinions expressed here but these postings sometimes contain completely inaccurate information, half truths and silly statements from those who have no professional credentials nor experience.
Go talk to the people who design yachts and build them.
Captain Mark and his manatee crew.

[Dockhead]

Originally Posted by Manateeman

WOW. The comments on twin keels. I guess I’ve got to go back to Ted Brewer and get a refund.
Let’s see. Two old guys. One has been building yachts for half a century and the other who has been designing yachts for half a century. What would they know?
Dear original poster.
You are having a vessel built for you. May I suggest following the suggestions of professionals. It’s nice to see the range of opinions expressed here but these postings sometimes contain completely inaccurate information, half truths and silly statements from those who have no professional credentials nor experience.
Go talk to the people who design yachts and build them.
Captain Mark and his manatee crew.

If that's a response to my post, the pros and cons of bilge keels are well known. I sail in an area where there is a quite high proportion of bilge keels. No owner of a bilge keel boat I've ever met disagrees that bilge keel boats are significantly worse upwind, than fin keel boats. That's why no racing boat in the world has bilge keels.


It doesn't take someone with "professionasl credentials" to understand why -- the efficiency of any wing is related to aspect ratio, and with bilge keels you also have significant effect on upwind performance of wetted surface ratio. Bilge keelers are inherently high wetted surface ratio and almost inevitably low aspect ratio*.



This is not a problem for the intended use of bilge keelers, and their owners typically love them. Most cruisers don't go upwind efficiently anyway; most cruisers anyway put on the motor. So losing some chunk of upwind ability is not really a big problem, certainly not for this intended use. And what you get in return is superb ability to go up estuaries, anchor where others can't, and work on the underwater parts of your boat for free on any given tide.



I love them myself and would definitely have a bilge-keeler as a second boat if I could afford it (like having a second wife at the same time, right? ). I would keep it in Cowes and have great fun all over the English channel estuaries.



* One French maker has built a radical bilge keeler intended to compensate for these properties: https://www.rm-yachts.com/en/rm-1070-en/ These are very cool, even if the idea hasn't caught on with other builders.

[Manateeman]

Dear original poster. If you google “advantages of twin keels” you will find a number of articles containing the opinions of the professional yacht design and building community. Some designers such as Naval Architect Douglas Phillips-Birt, feel twin keels are the “most exciting breakthrough since the Bermuda rig”.
Please also read the Patrick Bray Yacht Design article on the advantages of twin keels. Yachting Monthly 3/20/2019 Why Twin Keels.
Sirius Yachts new builds are about 70 to 80% twin keels.
Kasten Marine also has some advice. You could post on yachtdesign.net as well.
I think there are other, important advantages such as directional stability and roll dampening during heavy weather sailing.
My technical training in fluid mechanics was at a research laboratory close to MIT. My teacher was a fighter aircraft designer. Sailing has a lot to do with two fluids.
The keel design we chose was based upon strength, directional stability and roll dampening. Yachts sit a lot. Sometimes on the bottom, lots of time at anchor.
Rolling day and night at anchor? Skidding sideways down a huge wave offshore in a storm? Not for us. We felt the increased cost of construction and the significant increase in strength was well worth it. Lightly built fin keels are nice for racing but that’s not our design criteria. Again, seek out professionals with proven experience in aluminum yacht design and construction.
Captain Mark and his manatee crew of professional boatbuilders.

[Breaking Waves]

Originally Posted by Manateeman

seek out professionals with proven experience in aluminum yacht design and construction.

hmmm . . . . you mean perhaps like Gerald Dykstra & KM Yachts and Kees van de Stadt & Gebroeders van Enkhuizen - the specific rather experienced and highly regarded designers and yards the OP specified?

[kryg]

Another effective solution is the designer created in the design of my boat. His solution to help the boat track and not round up when planning down a wave, is from the back of the keel to the front of the skeg there is a sharp centre line V shape to give the boat directional stability. My boat tracks straight down the face of any seas, the effect is the boat slides like it was a bar of soap, but tracks in a straight line.

There is little leeway as a result of the hulls underwater sharp V configuration. This design was created and won an award in 1986, and it displaces 8.5 tons for a 15-meter boat. Granted it was water ballasted, however, in consultation with the retired designer. I saved 250 kilos by changing the standing wire rigging to 30 kilos of Dyneema. The boat and mast are aluminium, I never used the water ballast much anyway.

Mine is designed for open ocean boat - The one benefit of this design is the autopilot does not need to work as hard, at the same time the one draw back with the Sharp V hull configuration, is the boat is slow rounding race marks. Skoiern IV is designed for reaching and running, originally for the BOC single-handed race 33 years ago. Of interest the boat speed likes to sit in a speed bracket of 8-9 10, 11 knots for hours on end, it is its sweet spot. Then it jumps to 15 to 17 knots in the right reaching conditions. For this reason, lighter is better. Say as an example, a 14 to 18 tons would not have the legs of a lighter displacement boat. A heaver boat becomes even heaver as it needs heaver gear to control and match its displacement.

Originally Posted by Manateeman

Dear original poster. If you google “advantages of twin keels” you will find a number of articles containing the opinions of the professional yacht design and building community. Some designers such as Naval Architect Douglas Phillips-Birt, feel twin keels are the “most exciting breakthrough since the Bermuda rig”.
Please also read the Patrick Bray Yacht Design article on the advantages of twin keels. Yachting Monthly 3/20/2019 Why Twin Keels.
Sirius Yachts new builds are about 70 to 80% twin keels.
Kasten Marine also has some advice. You could post on yachtdesign.net as well.
I think there are other, important advantages such as directional stability and roll dampening during heavy weather sailing.
My technical training in fluid mechanics was at a research laboratory close to MIT. My teacher was a fighter aircraft designer. Sailing has a lot to do with two fluids.
The keel design we chose was based upon strength, directional stability and roll dampening. Yachts sit a lot. Sometimes on the bottom, lots of time at anchor.
Rolling day and night at anchor? Skidding sideways down a huge wave offshore in a storm? Not for us. We felt the increased cost of construction and the significant increase in strength was well worth it. Lightly built fin keels are nice for racing but that’s not our design criteria. Again, seek out professionals with proven experience in aluminum yacht design and construction.
Captain Mark and his manatee crew of professional boatbuilders.

[dannc]

Originally Posted by Walawala11

Thanks for your insights and offer to reach out directly. I am trying to get to the KMY open yards in a couple weeks. I will thoroughly go through the Bestevaers and Stadships at that time. I had planned to meet both KMY and Gebroeders van Enkhuizen at the HISWA show this weekend, but unfortunately the event was cancelled due to COVID restrictions.

The KM open day is September 18th and 19th. Real Soon Now.

Wish we could go. We had to cancel our 2020 trip and then the trip in 2021. Maybe 2022 will happen.

Later,
Dan

[dannc]

Originally Posted by Caleb_Grey

Distant Shores are doing this right now
https://youtu.be/esYdVPavwAI

I posted a link to SWL's and Nolex77's Classic Discussion on the Distant Shore YouTube channel, but it disappeared for some reason

Later,
Dan

[Manateeman]

Having a boat made FOR you, does NOT make you a boatbuilder.
Mark

[Breaking Waves]

Originally Posted by Manateeman

Having a boat made FOR you, does NOT make you a boatbuilder.

?

Are you trying to suggest that KM Yachts and Gebroeders van Enkhuizen are somehow not boat builders? That Gerald Dykstra & and Kees van de Stadt are somehow not designers? When in plain fact these are some of the best in Hollard. Dykstra is terrific to work with because not only is he a vastly experienced and knowledgeable designer but also has significant personal sailing experience (including to high latitudes).

Or are you trying to suggest that you know better than these top dutch professionals?

I just think you may have lost the plot here.

[noelex 77]

Originally Posted by Manateeman

Having a boat made FOR you, does NOT make you a boatbuilder.
Mark

And being a boatbuilder does not make you a yacht designer .

[Breaking Waves]

Originally Posted by noelex 77

.

hey, what draft did you end up with?

I could probably find it with search but since you are right here.

I liked 2.1m, just curious if you ended up with something significantly different than that. I know the design has quite a range of options available, including lifting keel.

[noelex 77]

Draft is 2.3m

[Breaking Waves]

Originally Posted by noelex 77

Draft is 2.3m

Thanks.

was there some specific logic for that number - eg a target harbour you wanted to be able to enter? or was it more just a 'generally useful balance between performance and accessibility'?

[dannc]

FYI, KM also built the hull of a Good Hope 56 designed by Ed Joy. The interior is being fitted out in Ireland.

This is a larger boat than the OP mentioned but it is an Aluminum boat, with a nice pilot house, and a massive lifting, swing keel. The boat can take the ground because of a swinging rudder design and the swing keel.

I believe five or so have been built with at least three being finished out by the owners.

Pet Peeve about keel terminology.

• We have lifting keels that provide lift and help the boat go up wind. These can be moveable or fixed keels.
• We have lifting keels that move up and down in the boat hull, i.e., lift, but may or may not provide lift.
• We also have swing keels that swing, possibly into the boat taking a little or a lot of space, or simply swing mostly on the outside of the hull, that seem to always be designed to provide lift.
• Then there are centerboards which seem to be swing keels but are not lifting keels.

Clear as mud?



The world "lift" can be confusing when discussing keels.

Later,
Dan