Schoal Keel w/Centerboard Performance

[clamcake]

Have sailed on many boats over the years but not one with schoal keel with centerboard.

In Florida, you are going to have problems in many areas with a draft that exceeds 5'.

A neighbor just bought a 1985 Irwin Citation 31. The draft is 4' and almost 9' with the board down.

I would be interested to hear how these boats actually perform with the board up?

Will the boat be tender in a good breeze? Reef earlier?

Obviously, she won't point as well.

Thanks!

[Pete7]

Downwind on a run, lift the board up and reduce the drag.

Sounds like a good choice for the location. We have taken a similar approach twin keels for sailing on wet grass

The photo on Sailboat data looks like she is going well. The D/R suggests she will be quicker than many.

https://sailboatdata.com/sailboat/irwin-31-citation

Pete

[clamcake]

Hi Pete-

Thanks!

He will be taking the boat to Punta Gorda.

Based on the charted depths, he will never be able to use the board.

So how will that boat behave with the board up 100% of the time?

[CruiseN]

We sailed a very flat swing keel. Handled great keel down. Keel up had no traction so through shoals of a foot depth we'd just have keel down a tiny bit. No problems with keel and reduced sail rotation but rudder slow where feel isn't liked. Having to move a long oar rather than a tapered edge.

Been looking at Adams13 though. I DON'T KNOW BOAT but besides obvious higher centre of gravity and maybe a rudder that isn't a kick up type hence a vulnerability if near grounding. Looks like they'd sail alright with a reduced area because they've nicely developed shallow keels.
I like that look. Looks like a fast full keel with addition of a dagger board and a deeper rudder 'sporting a tapered edge. Hence looks like she'll track well without heavy dagger board that seems to be easier to name as her keel.

I'd be more worried about rudder than sailing abilities in shallows with that model. IDK. That's just my opinion.

[Nicholson58]

Our 58 Camper Nicholson is decent with the board up. Boards are typically not heavy enough to count for heeling stability. Ours increases pointing ability about 3-5 degrees. We rarely use it.

[Captndave1]

I have a Citation 34 with swing keel, 4' board up, 8' board down. I race the boat and mostly race with board up, but when the winds are up, board down and point a few degrees higher. Very happy with the boat, winning races.

[psk125]

Friends who had a Bristol 35.5 sailed it with the board up all the time. It was too much work for them to let it down and then have to crank it up again. They didn't notice any difference in performance, but then, Gentlemen never sail to windward...

[roverhi]

There is a shoal keel and a Scheel keel. Assume the Irwin is keel/center board boat. If so boat will sail just fine board up though won’t point as high as it would with the board down or a deep keel boat. On most keel/cb boats the cb will have little, if any, effect on healing. Have owned two keel/CB boats and seldom lowered the CB. Boats sailed better off the wind with board up. Cruising/day sailing, the windward performance wasn’t improved enough to warrant dropping the board. If you are a racer or ocd might use the board more. Swingkeels are a whole other story but that’s not a hat you asked about.

[jas]

Have a Wellington 44 with 4'5" board up and 8' down. Modified full keel and use the board occasionally when looking to move along to weather. Very nice riding ole gal. (1980)

[bmz]

To give you some good insight on the keel affect, in the 2017 Irwin Rendezvous in Rock Hall Maryland, my deep keel 1983 Irwin 34 raced in a fleet which included a 1981 keel/centerboard Irwin 34 and a 1982 shoal keel Irwin 40. The handicapped and nonhandicapped finish order was 1) my Irwin 34, 2) the keel/centerboard Irwin 34, and 3) the shoal keel Irwin 40 (which, but for the keel, is the fastest of these three).

[SailSonoma]

I sail a Bristol 41.1 and do frequently sail upwind. I routinely take charter guests in a circumnavigation of St John which requires short tacking along Sir Francis Drake channel between Tortola and St John. I believe that my boat has a similar underwater profile to the Irwin.

Sailing with the board down (10' draft) increases pointing a little bit as previously noted, but more importantly it decreases leeway significantly. With the board up (4.5' draft) it looks like you are going where you want, but the boat tracks 10-15° to leeward. It makes for a very disappointing upwind leg.

Centerboard boats are designed to be sailed with the board down while going to windward, otherwise the architect would not have added them to the design

[Searles]

Sailed and raced an Adams Carine 44 long stub keel ,drought 4.3 ft unballasted c b board draught 9ft great boat fast comfortable ,off wind board up until balanced helm ,to windward board full down ,high and fast ,the best of both worlds. ⛵️⚓️

[malbert73]

My tartan 40 has a K/CB configuration. I really like it. I use the CB when sailing upwind. In breeze it really reduces leeway. And in a few races I have found that the 9 foot draft with the CB foil deployed helps reduce leeway in breeze better than deep keel vessels (which overall have less draft than my CB). Ie the CB gives me super deep draft performance as far as leeway though admittedly doesn’t place the ballast as low.
So if you sail in shallow areas it’s a great compromise. I’d rather have my setup than a wing keel.
And if you are in deep waters a deep keel will always be best

[Frankly]

To fill out the ticket: Sailing my IP32 keel CB for 16 years. As others have said reduces leeway heading upwind, maybe point a degree or two higher. Hardly ever put mine down knocking around in the Bays (3.5ft draft just tooo easy) around here but out in the GOM drop the board going to weather. On an IP lot of stability comes from hull shape and a big chunk of keel.

Bob Johnson's design makes up and down a breeze and maintenance at haul out just not a big deal. Only had the board out once in 16 years but that was so easy might just make it a regular.

The 3.5ft draft is the difference between behind my house and the trouble/ expense of a marina (no brainer).


Frankly

[MV Caroline]

C&C designed landfall series had Scheel keels with out centerboards, They were fast and good sea boats. I had a Landfall 38' (5' draft) and a landfall 43' with a 5' 8" draft. Both boats were fairly stiff and fast cruisers. both went to weather well also.