Fin or shoal draft.

sailcruiser · Dec 3, 2011

They won't point as high into the wind and can be a little more tender. SC

Squidd · Dec 3, 2011

sailcruiser said:
They won't point as high into the wind and can be a little more tender. SC

Can you put that into laymans terms or landlubber lingo...?

David in Sandusky · Dec 3, 2011

Plain talk

A shoal draft boat will point 5 to 10 degrees farther off the wind when close hauled into the wind than the same hull with a "full" keel. If we try to point our shoal draft '77 h27 closer to the wind, it makes leeway, that is, the wind pushes it sideways off the wind. It goes faster if we steer off the wind, and concede the 10 degrees we would lose to leeway.

10 to 20 degrees off close hauled, our shoal keel performs as well as a full keel.

A shoal keel weighs more than a full keel on the same hull to compensate for its reduced depth. As a result, a well designed shoal draft boat is no more "tender" than the full draft version. (Tender means the the boat heels more quickly and/or farther in the same wind.)

The advantage of the shoal draft is that it opens up a number of shallow water "gunk holes" that would ground a deeper draft boat. In our case, the manager of our marina said that he would not accept the 5 1/2 foot draft of the Catalina 30 we were going to buy due to low water in the channel to our berth. So we switched to the 3 1/4 foot draft of our Lady Lillie. In doing so, we opened up more Lake Erie anchorages than we realized!

Benny17441 · Dec 3, 2011

It would depend on what boats have you sailed previously. Boat hull shape and keel design has improved over the years. We have a shoal draft wing keel h320 and we do not feel like the boat gives away any pointing ability. The word tender implies a perception of lack of stability but no boat with a 3000 to 4000 lbs keel 4' to 7' in length can hardly be considered tender. We carry a large roach mainsail with two reef points and we do not start reefing until the wind clocks in excess of 25 knots and have carried sail in winds of 45 knots. No feeling of uneasiness. The boat is lighter than its older counterparts and will sustain a cruising speed of 6 knots with a double reef in winds approaching 30 knots. Because of the shape of the hull the boat sails best at shallow heel angles of around 20 degrees. If you want to get the most enjoyment out of a boat here in Florida you need a shallow draft boat. It seems like you already own the boat so the purpose to your question may be academic. Take her out a few times and then tell us what you think the differences are.

Ed Schenck · Dec 4, 2011

I'll disagree with Benny. The same boat with a fin keel will always be first to the windward mark. And a shoal draft, despite more weight, will usually have a worse "capsize ratio". In other words will be a little more tender. In Lake Erie and most of the east and gulf coasts a shoal draft is, unless you race, a real bonus. Where you are in California probably not so much.

DianaOfBurlington · Dec 5, 2011

Did we answer Squidd's or the OP's question?

For Bob and Squidd-- in short, as a general rule, it's this equation:

Deep draft = more stable, less heel angle; holds a tighter tack.

Shallow draft = heels earlier, heels farther (without necessarily being unstable); slips off a little to leeward more, especially being on a tight tack.

Centerboarders behave, a little less extremely, similarly according to where the board is set.

Boats with water ballast are outside both of these categories (and-- in my not-so-humble opinion, not recommended).

sailcruiser · Dec 5, 2011

Squidd said:
Can you put that into laymans terms or landlubber lingo...?

Sorry Squid I typed that in a hurry And realize it isn't lubberly friendly.

My comments come from sailing a shoal draft full keel boat as my first boat and a now deep draft larger second boat.

My B24 was a rock stable little boat once it was in to it's sweet spot which was about 20 degrees of heel. It hit that very quickly so it felt unstable but wasn't. I tried to broach (lay the boat over) but never could. I am one to try something controlled once to learn how to deal with things within reason. Hull design plays a part in heeling too. This boat was a V hull and gained its waterline when heeled (about 15-20%). The longer the waterline the faster you go. Boats with shoal draft have less lateral resistance than a deeper keel so they sail sideways a little more if you are trying to go too tight to the wind angle. (point higher)

My current boat is more of a champagne glass type hull and is much wider (beam). It doesn't need to heel as much to gain it's waterline (speed) and is quite happy around 10-15 degrees and gets here gradually as opposed to a quick tip in the old boat. With the deeper draft we can run tighter to the wind with less leeway.(slipping sideways)

So depending on your cruising grounds and the comfort of you and your crew should help you decide. My spouse does not care to heel let alone snap quickly to 20 degrees even when prepared. So the current boat doesn't do that and meets all the criteria on both our lists. If you sail around FL a shoal draft or centerboard style boat would be ideal. On the west coast deeper is easier to do. Lake sailing I'd probably go shoal as well or centerboard because of fluctuations in water levels.

I hope this is a little more clear in lubber speak. I'm hanging on tight to my sailing lingo since it's all I'll have until May. Let us know if you have any further questions. SC

Don Lucas · Dec 6, 2011

My last boat was a shoal drat with a massive wing and my current boat is a deep drat with a bulb.

My deep draft heels more than my shoal draft boat did.

My deep draft stands up better to gusts and heels over less during them.

Both boats pointed into the wind the same, the deep draft may not have as much lee way but who knows.

When grounding my shoal drat wing, it was really aground and there was no way you were going to heel the boat to get off (either have to be towed off or float off)

On my last boat it came either as a shoal or deep and there was note by the designed in the manual saying they believed the shoal would sail BETTER than the deep.

So in the end to me a shoal allows you to sneek in a little closer to anchor, while a deep draft takes less knocks down when gusty.

sailcruiser · Dec 6, 2011

Don Lucas said:
My last boat was a shoal drat with a massive wing and my current boat is a deep drat with a bulb.

My deep draft heels more than my shoal draft boat did.

My deep draft stands up better to gusts and heels over less during them.

Both boats pointed into the wind the same, the deep draft may not have as much lee way but who knows.

When grounding my shoal drat wing, it was really aground and there was no way you were going to heel the boat to get off (either have to be towed off or float off)

On my last boat it came either as a shoal or deep and there was note by the designed in the manual saying they believed the shoal would sail BETTER than the deep.

So in the end to me a shoal allows you to sneek in a little closer to anchor, while a deep draft takes less knocks down when gusty.

Don I've always been leery of wing keels. Perhaps because I haven't sailed one and my imagination gets the better of me. The wing may have been a factor in heeling less but I'm no architect nor real familiar in that area. The old 70s fixed keel Pearsons, Bristols and Contessas all got a lot of their waterline heeled a good bit. I say this because I've been on all 3 70s era. My Bristol had an 18' and change waterline not heeled and a good 23 once heeled over. I'm sure hull design is a factor here too. SC

Jackdaw · Dec 6, 2011

When comparing shoal vs deep keels, you have to compare the same boats. comparing one boat with a deep keel vs another with a shoal keel is useless.

All else being equal, (same boat), a deep fin keel will give you the best performance. The fin will point better by generating more lift, and it will typicality be (maybe 1000+ lbs) lighter, making the boat faster. Its lighter because it can have its CLR (Center of Lateral Resistance) in the same place, to balance out the sail-plans Center of Effort with less lead in the keel.

If you have to go places, do NOT underestimate a boat's ability to point on how fast it goes to windward. Remember you are not concerned with thru the water speed, but with VMG (Velocity Made Good) towards your destination. If a boat points 10 degrees higher than its shoal keeled brethren, it might have the same speed thru the water, but it will BURY it toward an actual destination.

Here's a sample. Two boats take off towards an anchorage dead into the wind. Same length, they both travel to windward at 7 knots. A boat that can sail into 45 degrees of AWA makes 4.9 knots VMG towards the anchorage. A deep finned model that can go 35 AWA is making 5.7 knots towards home. On a four hour trip, thats 1/2 an hour faster.

But as we all know, performance is not the only factor when boat buying, and often not even the most important one. Often the ability to just park the things is the driving factor.

Squidd · Dec 6, 2011

DianaOfBurlington said:
Did we answer Squidd's or the OP's question?

For Bob and Squidd-- in short, as a general rule, it's this equation:

Deep draft = more stable, less heel angle; holds a tighter tack.

Shallow draft = heels earlier, heels farther (without necessarily being unstable); slips off a little to leeward more, especially being on a tight tack.

Thanks, that's kinda what I thought it ment, but I've seen that phrase so many times, I wasn't sure if I truly understood it or just had an understanding of "familiarity"...

Rick486 · Dec 7, 2011

I think it's important also to remember that in sailing to a destination that is 20 miles to windward there are many other variables which typically come in to play as well. For instance, wind shifts. There are typically any number of wind shifts to be encountered during a 4-5 hour sail such that a sailor who notices and plays the wind shifts well will gain much Vmg. Also a sailor's ability to sail efficiently in waves can be a huge determinant of performance. Then there is sail trim. Regardless of keel configuration, efficient sail trim is a very big determinant of performance to windward. At the end of the day, unless a boat is to be used extensively in racing where all or most of the skippers are very good at all these other factors, I would always opt for a "shoal draft" keel for the flexibility it provides in choice of destinations. I personally raced one designs and cruising yachts and feel comfortable with all these other factors. In my mind the performance difference shallow to deep keel will easily be overshadowed going to windward by the collection of all the other performance determining factors. again, unless racing is the primary interest.

sandpiper10471 · Dec 7, 2011

Don't forget to consider the fact that there are two types of shoal draft fixed keelers. One has wings or winglets, the other doesn't. For example, most of the Cherubini Hunters were offered in two drafts, but neither had wings. The deep draft versions will beat the hell out of the shallow ones to windward. Later models of boats have shallow keels, making them shoal draft, but have wings. These wings increase the draft when heeling occurs and also reduce slip of water past the bottom end, thus increasing lateral resistance. At low speed they exhibit little lift and the boats tend to blow around a lot under power. But get the speed up under sail and they generally develop remarkable lift considering the shortness of the leading edge. Remember, keel lift cubes as speed doubles. Sail a shoal draft boat equipped with wings a little bit free to increase speed and you will see her gain vastly to windward.

quadrille38 · Dec 8, 2011

In isn't just Hunters, it is the same for all boats regardless of who makes them. It is a matter of hull design and preference. If you sail in areas with shallower waters a shoal draft, wing, or centerboard type keel is often preferred. Less chance of running aground.

A full keeler will be very stable, steer nicely in a straight line, tends to be heavier and will take more wind to get moving, and will sail more solidly in higher winds.

Fin keels tend to point higher but generally are longer requiring greater water depth.

Example - our 1987 Catalina 34 had a fin that drew 5 foot 7 inches.
Our 2008 Hunter 38 has a wing keel that draws 5 feet but is heavier than the same boat with a fin keel on it.

The cup boats tend to have very deep keels with the bulb.

Alan · Dec 10, 2011

My boat came with a shoal draft wing keel. Later I replaced it with a 6' draft fin and the transformation in the boat was nothing short of spectacular. She was faster, pointed higher and had much less leeway which was a real problem as the wind increased. Around here the depths run to well over 100 feet so draft is just not an issue. Considering all the gains the fin keel brought if you have the choice I would highly recommend the fin over the shoal keel, the difference is like night and day.

AtlanticAl · Dec 11, 2011

The winged keel was designed be the australian Ben Lexon, and financed by alan bond, It was the americas cup winner in about 86, it was good for that boat, but was a marketing idea for beneatau, and other designers "oh it has a winged keel" the things are deadly on a small boat in a following sea, they trip the boat up. No racing boats today use a winged keel, (well not that i know of, its eighties technology) round the world yachts, use hydralic tillting keels. But the basic question was, shoal keel over fin keel, well find keel lets you sail closer to the wind, i had a shoal keel, we couldnt get much better than beam on to the wind. But if you look at back in the day, all the old square riggers, were pretty much none keelers, and they did ok. If you look at a modern round the world racing boat, a fifty footer and you see it out the water, the keel is about fifteen foot long, with a bulb at the end of it, makes it go really fast, and stand really vertical but the pressures on rig and keel are incredible, as abby 17 found out when her rig got torn off.

Alan · Dec 11, 2011

The 'wing' as first introduced by the Aussies has nothing at all in common with the wings that are added to today's production boats. The original wings were designed and heavily engineered to produce added draft and lift as the boat heeled. The so called wings that are produced today are nothing more than additional weight added to the bottom of shoal draft keels and only serve to increase wetted surface area and additional drag. It was used as a marketing ploy and has remained just that. None of the racing boats of today use any sort of wing which should answer the question as to their true effectiveness.

Mariner356 · Mar 29, 2012

Alan said:
The 'wing' as first introduced by the Aussies has nothing at all in common with the wings that are added to today's production boats. The original wings were designed and heavily engineered to produce added draft and lift as the boat heeled. The so called wings that are produced today are nothing more than additional weight added to the bottom of shoal draft keels and only serve to increase wetted surface area and additional drag. It was used as a marketing ploy and has remained just that. None of the racing boats of today use any sort of wing which should answer the question as to their true effectiveness.

I question if the guy is racing. If not, I believe he'd like the shoal draft if he'd like to anchor in places near shore and get in closer in shallower areas. The Bahamas aren't friendly for boat drawing more than 5 feet. less than 5 is better. My 410 draws 5 feet and was available in deep draft at 6 1/2 feet. Too deep for the North Channel north of Lake Ontario and Georgian Bay.