Help! What are bilge keels really like to sail?

[bastonjock]

Chocks

i would assume that your intended cruising area is the west coast of Scotland,the benefits of a bilge keeler are more for the East Coast of England.My buddies used to keep an albin vega at Tarbet,they sailed her in anything,vegas are good strong little boats that go to wind very well.

IMHO,no need for a bilge keeler on the west coast

 

[rwoofer]

Question.

Do you think you would get the same advantages (shoal draft, ability to dry out) from a single keel with the same total weight paired with twin rudders engineered to support the boat when dried out? Especially if the boat was designed to sit back slightly when ashore.

That would seem to me to offer a slightly lower wetted surface area solution coupled with increased control under sail.

Good question that goes to the heart of why Marc Lombard went twin keel. The boat is wide to give good downwind performance. If you had a single shoal draft keel as soon as you had any heel on the efficiency of the keel would be dramatically compromised as it lifts out. By having a keel at the turn of the bilge it stays in deep undisturbed water still creating lift (the windward keel does start to come out reducing wetted surface area a little). That's why open 60's have daggerboards at the turn of the bilge, so that when heeling, they get max lift.

Personally I would love to have twin rudders as well, because with a very deep single rudder it does lose grip way before the keels.

The real disadvantage of wetted surface area makes itself most felt in v. light winds, especially with a great flat transom as well.

 

[davierobb]

snappy 26 bilge keel

I had a snappy 26 and it was a great sea boat, handled f7 and more and still made it home. As far as pointing up real sailors will Tell you that you can tack through 90 degrees if you can sail your boat well. This is almost true in perfect conditions but in a f5 > f7 then your are lucky to make 10 degrees to windward. The leaway is horrendous even reefed way down. I f you want sailing performance then only a good fin keeler will do.

 

[Fire99]

I had a snappy 26 and it was a great sea boat, handled f7 and more and still made it home. As far as pointing up real sailors will Tell you that you can tack through 90 degrees if you can sail your boat well. This is almost true in perfect conditions but in a f5 > f7 then your are lucky to make 10 degrees to windward. The leaway is horrendous even reefed way down. I f you want sailing performance then only a good fin keeler will do.

I wouldn't say a Snappie 26 is renowned as a benchmark for Bilge-Keel performance.

 

[grumpy_o_g]

The general consensus seems to be that lee-way is the biggest drawback - I'd always assumed it was wetted area and possibly slamming on some boats. Personally I hate the continuous keel slap some designs seem to have more than the slamming and I'm a big bilge keel fan.

Anyone can somebody explain to me why a boat which has two plates sticking down to stop it going sideways has a greater leeway than a single keeler, especially as one of the twin keels will tend to be more vertical for a given heel than a fin?

 

[Half Moon]

twin keels

I know it is a bit off the mark but, I agree with "boatmike" ; my cat has two shallow keels, goes to windward very nicely and can take the bottom if the tide goes out, and will never be the first to the mark in a race. However, a deep daggerboard model will be faster and point higher...and be significantly more expensive. There is that old saying for design; you can have any two of the three options; speed, comfort or low cost; ie speed and low cost but it will not be comfy...speed and comfort will cost you plenty..... low cost and comfort will not be fast....

~~_/) ~~ Half Moon

 

[William_H]

Bilge keels

Generally, there is truth in this.


Final point - we seem to have the largest population of BK's in the world - ie the rest of the sailing fraternity have not seen the advantages. You have to ask yourself why?

PWG

You would go a very long way to find a bilge keel yacht around Fremantle. Simply because they are not necessary one keel is quite enough. The reasons I think you find them only in UK is the large tides and subsequent large areas of shallows and the predominance of drying moorings. None of these are found here.

For a sail boat I think windward sailing ability is very important. You have a better chance of sailing off a lee shore and the ability in a blow to slow go usefully to windward while being some degrees off hard on the wind. A deep fin keel is the way top achieve windward performance. I would carry legs if I thought I was going to be stranded in shallows with a falling tide.

You are right (before you say it) that I have no experience of UK conditions and certainly if you can only get a drying mooring bilge keels or better a catamaran would be necessary. My own little boat has lifting fin keel so will sit in a few inches of water or happily on its flat hull bottom and it sails to windward as good as any. Yet over a season I would generally never lift the keel so things are different here. olewill

 

[nathanlee]

Bilge keels and good sailing ability don't go together IMHO.

Have a browse of this chap's website. http://thesimplesailor.com/

Here's a picture (from his website) that shows the voyages he's undertaken in a 21ft bilge keeled boat.

 

[Tommyrot]

Bilge keels, Junk rig and only 21ft, nah! Couldn't be done.

 

[Robin]

Over the years I have owned a centreplate boat, several bilge keelers and several fin keelers. I have to say the primary reason for the non-fin ones was that I had a drying mooring because once I had an affordable deep water mooring I was outa there fast!

When I owned bilge keelers it was indeed nice to be able to go places deep keelers couldn't, especially around Poole which is a shallow harbour. However that is a fairly limited horizon to have. Although my mooring dried I didn't like drying out, bump and bang disturbing sleep nicely in taking the ground. In fact in Studland (of seahorse fame) I mostly anchored in the same spot as I did years later with fin keelers and stayed well afloat rather than creeping inshore right off the beach as others did. OK in the yard in winter I didn't need a cradle, was shallow enough to reach the crane at my then club for really cheap storage ashore and could polish the topsides without a ladder, painting between the keels was less pleasurable but bearable.

Then, after a summer cruise west when the wind was strong and on the nose all the way and then turned and did the same all the way home I said my next boat will either have a fin keel or a big engine and preferably both! I hit lucky and got a licence to lay my own mooring in deepwater in Poole, yippeeee!! So I had my first fin keeler and the winds went my way and for a whole season it seemed every passage was downwind. The performance differences were huge but then the fin keeler was bigger too.

With our penultimate cruiser we had a Westerly 33 ketch with a fin keel for over 14 years. We once sailed that home from Southern Brittany in company with another one that had bilge keels, so many miles of comparison upwind and down and in all directions our fin keeler was significantly faster. Our friend's tactic was to let us get a mile ahead, then motor sail past us the same distance, start sailing again and wait for us to pass by yet again. The difference upwind was about half a knot boatspeed and lots of leeway degrees although the direction the bow pointed wasn't too dissimilar. Downwind however, even in seriously strong winds when we did 110mls together one leg with a tailwind 45kts apparent, up to 55kts true, the speed difference was still around half a knot. Now the bilge keeler W33 was just as safe and dry as was our fin keeler despite horrendous seas from a week of gales before our trip, but the speed difference was unexpected.

My feeling is that above a certain size you need to have a decent amount of keel depth underneath and a 40 footer with twin keels drawing say 5ft would be in chocolate teapot territory as far as drying moorings are concerned. The W33 bilge keeler draws 4ft by way of comparison, already pretty deep in the drying moorings stakes. Without some decent lateral area in undisturbed water under the hull, sideways is a likely direction to go. The second (windward) keel area is 'hidden' behind the lee side one which is the one resisting the leeway and is doing nothing except add to the amount of drag resistance from friction.

So whilst there are undoubted advantages to bilge keelers the reality is that you will give up significant performance especially upwind and this will be most marked as the wind and seastate increases. Sure there are some better than others but then that applies across the board because there are some poor performing keel boats too.

There really is no such thing as a free lunch, compromise if you want but do so knowingly for the right reasons in your particular case, not under some notion that the difference isn't noticeable.

 

[rwoofer]

The general consensus seems to be that lee-way is the biggest drawback - I'd always assumed it was wetted area and possibly slamming on some boats. Personally I hate the continuous keel slap some designs seem to have more than the slamming and I'm a big bilge keel fan.

Anyone can somebody explain to me why a boat which has two plates sticking down to stop it going sideways has a greater leeway than a single keeler, especially as one of the twin keels will tend to be more vertical for a given heel than a fin?

Your assumption that wetted area is the main drawback is correct. You can design out some of the wetted area by using minimal chord length (which also stops any slamming).

Leeway is very much influenced by the design of the keel (and a bit by the hull). Modern twin keels have shorter chords and tend to have a slight toe-in to increase the angle of attack (has the added benefit that the upwind keel is helping righting moment). Net result; no difference in leeway.

As you might expect wetted surface area has most impact in light winds, which is where notice it. However I think that large wide transoms have an even bigger impact in light winds than the extra keel.

 

[Slow_boat]

Any thoughts anyone?

Creek crawler, able to take the ground. Plus s/h offshore ability in big wind and seas?

You are asking too much.

With my old Macwester you would be right.

But with my Sadler 29 I beg to differ. She is a great seaboat and the bilge keels mean I can use a mud mooring at £100 pa. If the windward keel slams then you're heeling to much. She probably isn't so close winded as the fin version but not by much.

Also look at Trapper 501 and Westerly Merlin. Fulmar is good but a bit bigger than you're looking.

 

[webcraft]

Started sailing in 1944, always avoided twin keelers until 2007 when my wife and I decided we were too old for long distance sailing. We thus looked for a boat suitable for sailing on the South Coast with occasional visits to France; much of our sailing is around the Isle of Wight. So we purchased a Westerly Merlin. Never been out in anything more windy than a force 7 (except on the Solent where we once were out in a force 8). The Merlin (28 ft 8ins) has never given us any cause for alarm, handles well in strong winds, points much better than I expected and is satisfactorily quick enough for cruising. Never had any problem with the so-called weather keel slamming (but this may be because the Merlin's keels are closer together than many other designs). There are so many advantages obtained from a twin keeler that I would recommend them unless you are going in for performance sailing.

A friend sailed a Westerly Merlin to the Caribbean from Scotland. Pointing ability may not be the most important consideration on that route, but he had no qualms about the seaworthiness of the boat. Mind you, he didn't know much about sailing either . . . .

- W

 

[Robin]

Lots of good bilge keelers getting mentioned here and yes some truly admirable voyages have been made in them.

However I stand by my earlier comments, they are a compromise and come with downsides which may or may not be important depending on the intended use.

It is also worth pointing out )) that pointing itself is irrelevant, the relevant part is the angle to the true wind that the boat makes. Lots of boats can 'point' close to the wind and yet the total angle including leeway they achieve is pathetic. Making comparisons in light to moderate weather too is not indicative, the real test is in rougher weather when the surface waters are stirred up, because that is when a deeper single keel really comes into it's own.

 

[Tommyrot]

they are a compromise and come with downsides which may or may not be important depending on the intended use.

So true.

True of every type keel,number of hulls or type of rig of course.

I stand by my earlier comment.

 

[Robin]

So true.

True of every type keel,number of hulls or type of rig of course.

I stand by my earlier comment.

I hope you don't think I'm looking down my nose at bilge keelers, referring to your earlier post, because I wasn't intending to and if you looked at my earlier offering I pointed out that I had owned several myself over the years.

I agree too that all boats are a compromise as you say.

However what I do say is don't simply shrug off the downsides as myth as some seem to do, because that is simply wishful thinking. Make a decision based on eyes wide open and that is the best you can do and even then no two people will have the same priorities or solutions.

The bilge versus fin debate is in many ways similar to the slab reefing mainsail versus in-mast one. There are plenty of people who will argue all day that there is no loss of performance or that it is too small to detect but the reality is different. Again not to say that either is the only or the best solution (junk rig might be one...) but that the decision should be made eyes wide open, there is a noticeable performance loss traded for the convenience of in-mast, just as there is for bilge keels.

 

[Tommyrot]

I hope you don't think I'm looking down my nose at bilge keelers, referring to your earlier post, because I wasn't intending to and if you looked at my earlier offering I pointed out that I had owned several myself over the years.

I agree too that all boats are a compromise as you say.

However what I do say is don't simply shrug off the downsides as myth as some seem to do, because that is simply wishful thinking. Make a decision based on eyes wide open and that is the best you can do and even then no two people will have the same priorities or solutions.

The bilge versus fin debate is in many ways similar to the slab reefing mainsail versus in-mast one. There are plenty of people who will argue all day that there is no loss of performance or that it is too small to detect but the reality is different. Again not to say that either is the only or the best solution (junk rig might be one...) but that the decision should be made eyes wide open, there is a noticeable performance loss traded for the convenience of in-mast, just as there is for bilge keels.

Definitely not singling you out, I agree with all of the above. I've sailed long and fin keeled boats and enjoyed them all. Sailing a triple keeler tomorrow!

It's just that I often feel that the drawbacks to bilge-keelers are a little overstated on here, while the disadvantages of a deep keel are ignored.

There is a small but vociferous section on these forums who "know" that the rest of us should be doing things there way.

I've got a bilge keeler which dries out twice a day. I've got a junk rig which I can easily use with my health/mobility problems, it will sail (downwind) in a strong fart while other boats use their engines. It suits me.
I heard from an ex junk sailor who returned to a bermudan as it was too easy and he got bored.

One man's meat and all that....

 

[Robin]

Definitely not singling you out, I agree with all of the above. I've sailed long and fin keeled boats and enjoyed them all. Sailing a triple keeler tomorrow!

It's just that I often feel that the drawbacks to bilge-keelers are a little overstated on here, while the disadvantages of a deep keel are ignored.

There is a small but vociferous section on these forums who "know" that the rest of us should be doing things there way.

I've got a bilge keeler which dries out twice a day. I've got a junk rig which I can easily use with my health/mobility problems, it will sail (downwind) in a strong fart while other boats use their engines. It suits me.
I heard from an ex junk sailor who returned to a bermudan as it was too easy and he got bored.

One man's meat and all that....

Ah so I'm included but not alone then!

Thing is if someone asks for an opinion then I think it is better they hear what I really believe rather than get a watered down general comment designed not to hurt the feelings of someone else. This is always the case with boat types or makes, because one persons dream machine is another persons nightmare!

The disadvantages of a deep keel are well known and fairly obvious so maybe that is why more emphasis is placed on the disadvantages of bilge keels?

BTW, 3 of the cruising boats I owned were triple keelers, 3 were fin keelers and one a centre plate so an even spread but I've also sailed lots of miles on many many more from a long keeled Pilot Cutter down to a Merlin Rocket via flat out racers.

 

[Tommyrot]

Ah so I'm included but not alone then!

My apologies Robin, poorly worded reply on my part. You are not included.

 

[wotayottie]

I'm a firm believer that you only get really worthwhile comparative boat performance data by racing it - impressions formed whilst cruising are just that - impressions.+

I raced a modern bilge keel boat in a competitive fleet on the PY handical system. The boat was a Moody 336 which in fin keel form rates similar to a Sigma 33 so its a decent hull. On a PY handicap of 1050, the boat was a race winner.+

I've now changed to a fin keel Starlight, a boay with a good rep and on a PY of 940 I am struggling a bit. A handicap of 970 would put me in much the same position as the Moody ie the Starlight on a fin is maybe 8% faster with a very similar waterline length. Sail area to dispacement is similar too so its not a power difference

That extra speed is wholly when hard on the wind and it isnt speed through the water but pointing ability. On a reach there is little difference except perhaps leeway if well heeled. Downwind the Starlight rolls a bit more.

Dont know about you, but whilst I love a good thrash to windward for an houyr or so racing I wouldnt want to do the same thing when cruising. Indeed if it werent for the racing I would go for a bilge keel every time just for the ability to get into the attractive estuaries and drying harbours. Which do you like most? MD marinas or places like Mousehole?

But the trick is to get a modern bilge keel. The sort you saw on 60s Brit boats ie ones parallel to each other and very shallow are an absolute liability.