Why are keels on boats so different?

[Nostrodamus]

Being out on the hard and anti fouling I cast my eye on the numerous other boats out of the water and every keel seems to be different.

Now come on.. man has had a few centuries to develop the most efficient keel there is but no.. he wants to add bulbs, wings, make them long, short and even ones that drop off.

Why are there so many keel designs?

Whilst I am on the subject of anti fouling I spent the last several days making the hull as clean as possible so it glides through the water better. I have folding prop so it is more efficient at sailing. I even spent 10 minutes trying to get a brush hair out in case it slowed me down and I knew it was there. Everything was looking smooth and nice but then what did I do. I added a huge great brick of a anode with the looks and streamlining of a London bus!

 

[AndrewfromFal]

Why are there so many keel designs?

Because there isn't a one size fits all solution in terms of keel design. Type of sailing done, the nature of the area one wishes to sail in and cost will all influence what kind of appendage(s) are the 'right one', not to mention aesthetics, technological advances and the vagaries of fashion too, as well as Hull form, of course.

 

[Tranona]

Why are there so many keel designs?

For exactly the same reason as there are different boats, cars, aircraft, wines, women ... or anything else. There is no one solution to all problems, nor are all problems the same. So there are many different keels.

Simples.

 

[KellysEye]

The ones I can think of are long keel, long keel with cutaway forefoot, fin keels, twin keels, narrow keels with bulb keel with fins , lifting keels and I can't remember the name but the keel that is about half the boat length in the middle. Others may remember more.

Long keels are for heavy displacement boats which have the kindliest sea motion. Fin keels are standard for AWB's.Twin keels are for taking the ground when the tide is out. Narrow keels with bulb or bulb and fins are racing boats. Lifting keels are for shallow water and the one I can't remenmber is on medium displacement boats for longer passages.

 

[Twister_Ken]

the one I can't remenmber

Fin and skeg?

 

[jimbaerselman]

Now come on.. man has had a few centuries to develop the most efficient keel there is but no.. he wants to add bulbs, wings, make them long, short and even ones that drop off.

Why are there so many keel designs?

Because old boats survive
And new boats are bought, optimised for different purposes:

To exploring nature in the shallow swatchways, drying out on the mud
To manouevre from marina to marina for pub rendezvous
To win races
To potter port to port in nice places and nice weather
To gain adrenaline shots by facing challenging passages in challenging conditions
To go round the world
To live on board in a quiet harbour

But you knew that already. So you're trying to get members of each of these groups to argue the case for their take on the sport?

 

[Nostrodamus]

Because old boats survive
And new boats are bought, optimised for different purposes:

To exploring nature in the shallow swatchways, drying out on the mud
To manouevre from marina to marina for pub rendezvous
To win races
To potter port to port in nice places and nice weather
To gain adrenaline shots by facing challenging passages in challenging conditions
To go round the world
To live on board in a quiet harbour

But you knew that already. So you're trying to get members of each of these groups to argue the case for their take on the sport?

No Jim, no argument in this question at all. Just we are out of the water amongst about a hundred or more other boats. All the keels seem to be different even amongst the same class of boats and I just wondered why. I can understand about 6 different designs for various classes but the rest are beyond me. Even on the same type of boat I would expected that some type of design would dominate but they don't.

 

[NormanS]

"a hundred or more other boats".

Why so many boats out of the water in the middle of summer?

 

[Nostrodamus]

"a hundred or more other boats".

Why so many boats out of the water in the middle of summer?

A lot of people in Greece find it either too hot or two crowded so they lay their boats up for a month or two in the summer. Others keep them here but can only sail a few times a year so keeping them on the hard is cheaper.
There is one total idiot I know that for reasons beyond his control is sat here in 39 degrees scraping , anti fouling and polishing his boat. The good news is we will be back in the water in two days.

 

[Sybarite]

The ones I can think of are long keel, long keel with cutaway forefoot, fin keels, twin keels, narrow keels with bulb keel with fins , lifting keels and I can't remember the name but the keel that is about half the boat length in the middle. Others may remember more.

Long keels are for heavy displacement boats which have the kindliest sea motion. Fin keels are standard for AWB's.Twin keels are for taking the ground when the tide is out. Narrow keels with bulb or bulb and fins are racing boats. Lifting keels are for shallow water and the one I can't remenmber is on medium displacement boats for longer passages.

Scheel keel,
Collins Tandem keel
Pivotting keel
Horizontal keel (acts like a wing)

 

[SamanthaTabs]

A lot of people in Greece find it either too hot or two crowded so they lay their boats up for a month or two in the summer. Others keep them here but can only sail a few times a year so keeping them on the hard is cheaper.
There is one total idiot I know that for reasons beyond his control is sat here in 39 degrees scraping , anti fouling and polishing his boat. The good news is we will be back in the water in two days.

Idiots united! Hope you're not next to the boat with the security dogs? Wow did that stink plus they were eyeing tommy up as a Scooby snack... Not never again lifting in July, never!!!

 

[Tranona]

No Jim, no argument in this question at all. Just we are out of the water amongst about a hundred or more other boats. All the keels seem to be different even amongst the same class of boats and I just wondered why. I can understand about 6 different designs for various classes but the rest are beyond me. Even on the same type of boat I would expected that some type of design would dominate but they don't.

Keel shapes go in and out of fashion and you can indeed get more than one keel type on the same model boat. My new boat has a shoal keel which is a very different shape from the standard deep keel, with a much larger bulb to keep the ballast and stability the same. Was also the case on my last boat. Think you will find most modern boats offer at least 2 different keels and sometimes (like the smaller Jeanneaus) even 3. So take a cross section of boats made in the last 20 years alone you will see a huge variety of shapes. The dominant types on mass produced boats, for fixed keels anyway, are bulbed or T shape as this is one of the ways designers can meet stability requirements with lower ballast ratios. Improvements in casting techniques have also made more complex shapes possible.

 

[Nostrodamus]

Idiots united! Hope you're not next to the boat with the security dogs? Wow did that stink plus they were eyeing tommy up as a Scooby snack... Not never again lifting in July, never!!!

They put cats in a different place of their own. We are just behind Rod Heinkels boat if anyone wants me to leave a note for him! Nice boat he has and very well looked after.

 

[Halcyon Yachts]

Have a look at the Dockrell 27:

Pete

 

[AndrewfromFal]

Have a look at the Dockrell 27:

Pete

Is that some sort of lesson in the dangers of kit built boats?

 

[SamanthaTabs]

They put cats in a different place of their own. We are just behind Rod Heinkels boat if anyone wants me to leave a note for him! Nice boat he has and very well looked after.[/

Boss says I'm not allowed to say what I think...

 

[Triassic]

Keels? Antifouling?

What are these things you speak about.......

 

[Twister_Ken]

There's also lead vs iron. Lead, less of it for same weight, so a smaller keel (probably smaller in chord, not in depth). Iron, more needed, so bigger (read wider) keel.

 

[KellysEye]

>Fin and skeg?

The boats I'm thinking of certainly have skeg hung rudder but the keel is about the size of half the length of the boats. It's so annoying I can't remember.

 

[LittleSister]

Have a look at the Dockrell 27:

Pete

Is that some sort of lesson in the dangers of kit built boats?

.
The Dockrell 27 is a reworking by Dockrell, with a reduced depth keel, of the Ian Anderson designed Hurley 27. Presumably they bought the rights to the Hurley 27 after Hurley went under.