Heel as an indicator

[Stede]

One "rule of thumb" I've always followed on monohull boats is that modern light displacement hulls will sail best at angles of heel around 20 to 25 degrees.If with the sails correctly set,your heel angle is consistently more than 30 degrees, you probably have too much up. Do you agree with this "rule of thumb", or is there another diagnostic tool you use in regard to the heel of a boat?

[delmarrey]

That's fairly true for my vessel. 20- 25 degrees is where she goes the fastest. More then that, she wants to weather up and start draging the rudder. Then it's time to change the foresail.

[Jeff H]

Actually, most really modern designs sail fastest at 5 to 15 degrees of heel. More than that is slower and unnecessary. They will sail OK at larger heel angles (and will still be considerably faster than older designs) but it is less than ideal and with thier significantly higher stabilities, larger heel angles are really much less common.

IOR era boats like Delmarrey's typically sail better at larger heel angles than modern designs typically at thier best in cruising mode in 15 to 20 degree range but again are typically faster at flatter heel angles, especially power reaching.

Older CCA era boats like very large heel angles (20-30 degrees)(increases waterline length and reduces wetted surface) and so generally hit their top speeds with thier rails closer to the water.

Jeff

[Stede]

Hi Jeff,and all,

I was hoping you would respond to this post Jeff and teach me some things I didn't know. Thanks for your input and sharing your knowledge

Delmarrey,

What kind of boat do you have? I've looked at her pictures here and she has lines of a real beauty,but I couldn't decide what mfg.I thought she might be made by. Wauquiez(sp) maybe?

[bradbarrett]

Jeff...the way I desribe it to crew on a newer (rounded/flat bottom wide boat that gets it's stability from form) is "sail it like she's a big dinghy... nice and flat", with the reminder oft' spoke "Remember, flat is fast"...

[delmarrey]

Stede,
It's a custom built by Choate in Long Beach, CA. The hull is so close to a Swan that you have difficult telling them apart. I'm actually going to rearrange the cockpit to be like the Swan except I'll open up the transom.

And Jeff is correct on the 15 - 20 degrees for a reach or close reach but, on a close haul I can't keep her off her side without loosing speed. She's only 14,000# which makes her pretty light for her size. If we had a crew of 6 or 8, hanging on the rail it would probably flatten her out a bit. Flatter is faster but I need more balast.
On a reach with white caps, I actually had her up to 11.6 knots COG but I believe I was going with the tide at the time.
I have another S/V, that's a 23 twinkeel trailerable that once it reaches hull speed it just starts heeling more and more until it's just dragging the rudder sideways.

[Stede]

Hi Del,

It sounds like your boat is a Cadillac with a Ferrari engine Nice!

[delmarrey]

That was SOG.

Cadillac?? Well, she's old and in need of a lot of TLC. But, the mast and wires are only a couple years old and the motor looks and runs good with about 7000 hrs. I had to tear out the whole head liner so I could seal all the deck fittings and do repairs to the deck where the water had been leaking in for a while. She needs a lot of up grades as well and new sails too. But I got her for a quarter and she's dry now. She's a bit of a project but she sails when ever I want/can get out there!

[Stede]

delmarrey,

This is kind of a side item to the original topic, but when you mentioned tearing out the headliner on your boat,it made me think of my boat. Mine has a fiberglass liner.While it looks great,it really makes access to deck fittings,etc. an engineering marvel to behold.In several places I've drilled large holes through the liner to gain access,and then install a piece of white teflon as a cover to try and blend back in with the rest of the liner.Having the liner in the boat truly is a love/hate relationship for me.When I buy another boat,I will pay a lot closer attention to areas of deck hardware access.It sounds like you've got quite a project going on.Your boat does have nice lines and I'm sure when you finish your modifications,she will be a sight to behold.What size is your boat?On my PHRF list,I could only find a Choate 40 with a PHRF of 81. Now that's a lean,mean,sailing machine!!!

[delmarrey]

Thanks Stede, I never thought of looking up the PHRF. I only knew she was streamline, light weight and slid along with almost no wind.
She' is the Choate 40. Used and abused but still hanging in thar.
First fiberglass vessel that I've seen with stringers running fore and aft as well as up and down in the bow section. The hull is an average of 1-1/4" with foam core and the deck 1" with balsa core. If she has 2000 more pounds of ballast it would actually increase the length of the waterline. The transom hangs out over the water about three feet and the top of the rudder shows out of the water. If I could ad a 2000# bulb or wing to the bottom of the keel I could probably get more speed out of her. The 140% genny is too much sail most of the time on a close haul.

As for the head liner, it was all stapled in. I must have pulled a thousand staples. It has cosmetic struts running across the ceiling and I'm just going to cover door skins and use screws to hold them in place. Then when I need to access under a winch or deck fitting again I can just remove screws instead of all the trouble of a sheet of vinyl. And if I back it up with foam it would be a good insulator as well.

[GordMay]

Delmarrey:
Most powerboats I've worked on use continuous strips of Velcro to fasten the overheads. Glue & staple (Monel or S/S) velcro to the cleats and skins.
It seems to hold up OK.
Gord

[Jeff H]

Interesting thread here. A couple quick comments:

bradbarrett's point about sailing these newer designs like a dinghy is spot on. Just like a dinghy they really do respond to changes in heel angle and trim. On the other hand I disagree that the current breed of IMS type form boats that I was referring to are "rounded/flat bottom wide boats that gets their stability from form". One of the neat things about the newer designs is that very little of thier stability is from form stability. Far less even than on older designs going back to the beginning of the 20th century. By far thier high stability levels comes from an extremely low VCG which is both good for motion comfort and ultimate stability. On the other hand I was vague in my description of 'modern boats' and so left the door open for comments about 'Open Class' derived designs which are heavily form stability types and not very appealing to my tastes.

With regards to Delmarrey's boat, at the time that these boats werebeing designed, the IOR was overly discouraging stability. Boats like Delmarrey's counted heavily on 2,000 lbs or more of crew weight on the rail for stability. Without that kind of moveable ballast these are pretty slow and hard boats to sail upwind as compared to later designs that had much higher ballast stability. Simply adding 2,000 lbs to the keel (even as a bulb) would not hep this much. While it would improve stability some, this would be offset by the higher drag of the bulb. That increased drag would result in an increase in heeling and reduction in speed partially negating the gains in stability. Additionally the increased drag from the bulb would rob speed on all other points of sail.

A better course of action would be to swap out the keel for a lower drag/ higher lift keel with a bulb of the same weight as the existing keel. That would improve performance on all points of sail.

Fore and aft stringers was fairly common during the era of the boat in question. This was an era when designers were just getting a handle on properly engineering of fiberglass boats so that they could be both lighter and stronger than the boats that came before.

Choate (is) was a first class builder.

Jeff

[Stede]

Jeff,

If I understand your comments correctly, it sounds like the best solution to improve stability on all points of sail for Dels boat,would be to change out the existing keel for one with a deeper draft,but that has the same weight as the current keel. Is that correct?

[delmarrey]

Stede,

I believe Jeff was refering to the modern keels being used today like the one on the home page of the following site, a long narrow keel with the ballast all at the end. Not necessarily any more draft.

http://www.denchomarine.com/index1.html

This keel has very little drag but still mantains the stability. This is one of Choates newest speedsters. A long waterline compaired the OAL.
The Mari-Cha IV that Troubledour has refered to, I believe also has the same keel from what I can see in the pictures.

As for my vessel, I don't think I would want to sink that much money into a vessel that I'm just playing around with and training the second mate for future adventures. So for now, I'll just live with what I have and be happy!

.................._/)

GordMay,
The velcro for the headliner is a pretty good idea. I may just do that! Thanks!

[Stede]

Hi Del,

Thanks for the info.and the supplied link. It answers my question. I was speaking strictly hypothetically as far as replacing the keel of your boat. If I had your boat, I would be very happy too