Full keel vs fin keel for offshore?

[thomm225]

Both full or fin keel will work.

You can take you pick from here:

Sailboat Reviews of Offshore Cruising Yachts : Bluewaterboats.org

[toddster8]

Anecdotes can be found about boats lost due to damaged spade rudders. As owner of one, I ponder the rudder shaft log... not only is it inaccessible behind the liner, but unlike the bow area, it is not protected by a crash box. I think this is something that could be fixed with a project of only moderate difficulty.

[Suijin]

Originally Posted by SV DestinyAscen

In our industry this is called survivorship bias. Old examples of well built ships and boats survive and give the illusion that things used to be better.

...And in fact the reason that old examples of well built boats are still around is that they were well built and retain value. I'm pretty sure that the general fiberglass production techniques of today are superior to what they were 30 years ago. What was once over-built out of lack of data on how fiberglass would perform over time is now purpose-built for it's intended use. But there were plenty of "under built" fiberglass boats of that era.

I worked in the Seafarer Yachts factory as a teenager. It's no mystery to me why you don't see many of them around anymore. They were chopper gun boats and most of them are now in landfills. So just because a boat is 30 years old does not make it a "good ol' fiberglass boat."

[Mike OReilly]

I cruise with a true full-keel boat. My previous boat was a modified fin (similar to a Valiant). If keel design was my only criteria I’d choose the modified fin with skeg hung rudder over my full keel with barn door rudder.

That said, keel design would not be/has not been a primary factor when looking for boats. I would not base my choice solely, or even largely, on keel design. In my opinion there are many, many other more important factors when choosing a cruising boat than keel design.

I like my current boat very much. A full keel has many advantages (excellent tracking, easy helm, safe/solid, easy on the self-steering, easy hove-to…). But there are also significant disadvantages, mainly to do with tight maneuvering.

Keels, like everything else on a cruising boat, is a compromise. No such thing as the perfect anything.

[Tidjian]

Originally Posted by Dockhead

This is a good point. There can be a lot of daylight between the strength of the keel of a boat built primarily for speed, or racing, with less consideration to strength, and that of a boat designed to be a robust cruising boat, even a fast one. Fin keels of the second type can be quite immensely strong.

Like Suijin, I've hit stuff with my fin (actually bulb) keel without damage. In my case, solid rock -- an uncharted rock in the Baltic. A dent the size of a coin in the 8 ton lead bulb was the only damage.

I think this is where I can see the safety merit. A full keel I suppose makes the boat stronger from bow to stern. Given that I can also see the protect of a rudder hidden behind the keel as it's less likely to break off. I could also see how this might make the boat slower and feel like an 84 new yorker when steering. But as someone pointed out she steers straight with not as much sensitivity. I'm not sure how much that last part matters since I'm going to try to snag a windvane system if I can.

I think my bigger fear isn't the crossing itself so much as once I get there. Since I'm not familiar with coastal sailing or reefs it does make me a little nervous. Even depending on a sonar or depth sensor still doesn't give me a sense of comfort. I'm worried I'm going to sail dead into a huge rock or coral reef under water and the boat will come to a dead stop and tear the keel right off. Maybe im being a little dramatic? I guess it will be one of those things I need to experience it myself to understand. When you guys say you've smacked things and only put a coin sized dent in your keel I feel a bit more at ease.

I'm definitely a big fan of the Vega and there are some within range of me within my budget. Not rushing into one but I like the style of her. I'm still a fam of the Columbia 26 MK II despite it being a fin keel. I'm assuming that model is a bolt on keel like my Grampian. I'll check out some more suggestions you guys have made. I was just trying to understand the difference. Thank you for your many replies.

[Pete7]

Originally Posted by OceanSeaSpray

... in practice, ALL single rudders are protected by the keel and the main function of skegs is destroying the hydrodynamics of the rudder foil by causing the flow to separate at the knuckle on the low pressure side.

It is rather hard for something to hit the rudder at sea when there is the deeper fin keel clearing the way exactly in front of it.

You won't mind if I disagree

There is nothing stopping a lobster pot going straight into the prop of my twin keeled yacht. Equally something like a tree log would go straight into the skeg and rudder, indeed the keels might even help it

However, for creek crawling the advantages still outweigh the downsides.

Pete

[Dockhead]

Originally Posted by robert sailor

Yes a really well designed skeg is just fine but a really well designed spade can be every bit as strong or stronger and the spade will always out steer a skeg rudder. Some skeg rudders were so poorly built that the rudder was holding the skeg on. Not my words but the words of designer Robert (Bob) Perry. It's actually really hard to build a skeg that is truly strong. The mass produced spade rudders built today have had flaws in several of the builds, especially in the structure that supports the rudder and these boats should be very carefully looked at and possibly improved before considering them for offshore.

We've done this discussion a few times already, and different people have different opinions, but I agree with Robert Sailor, as well as with Bob Perry and Steve Dashew (and probably all the rest of the world's great designers) and have a strong preference for (properly designed and strongly built) spade rudders.

My present boat doesn't have a spade rudder, but the next one sure will.

[K_V_B]

Originally Posted by Dockhead

We've done this discussion a few times already, and different people have different opinions.

There is an interesting thing how each sailing region has its own set of prejudices...

You notice that when you read different sailing magazines...

For the French the best Water boats">blue water boats don't have a keel at all. The French love centerboards.
For the Dutch "blue water" is synonym with "Koopmans".
In the US many seem to believe that a boat needs to have a bow on both ends...

And so on.

[JPA Cate]

Tidjian,

It is close attention to charts and looking into the water where it is clear that keep you away from hitting hard bits. I really think hitting something some time is almost inevitable if you cruise in poorly charted waters, or poor visibility conditions. We all try to avoid rocks and coral heads, but, at least ourselves, we have had one hard hit with both of our last two boats, and a few light touches.

Both boats we've done lots of sea miles in have been fin keel, skeg rudder boats. One of them had a flush deck. If, in the size range you are looking at, you can find one that lights your candle and has a flush deck, you may find that a better situation, as your coordination is unlikely to improve, and you will have to go forward at sea, on occasion. When you get to the point of outfitting the boat for the journey, consider central placing for your jackline.

A.

[sv.antea]

There is one aspect of the choice that hasn't been mentioned here. Yes, long keel would tend to make the hull stronger, but fin design and construction can offset that. If you are going slow, as when negotiating an iffy harbor entrance or anchorage and you hit a rock, the long keel boat will tend to stop dead, whereas the bottom of the fin keel will stop dead as well, but not so the rest of the boat. It will pivot forward over the obstruction and sometimes bounce back. The damage may not be so bad. Ask me how I know.
The other difference is that when you run hard aground on sand, I believe you will have easier time getting off without outside assistance with a fin keel boat. Fin keel boat can be usually wrenched around easier, (motor or kedge) so it points more towards the deeper water and wiggled free. Full keel boat can actually ride up on the shoal further and higher, lacking the aforementioned pivoting/pitching forward bit.

[Cheechako]

Originally Posted by sv.antea

There is one aspect of the choice that hasn't been mentioned here. Yes, long keel would tend to make the hull stronger, but fin design and construction can offset that. If you are going slow, as when negotiating an iffy harbor entrance or anchorage and you hit a rock, the long keel boat will tend to stop dead, whereas the bottom of the fin keel will stop dead as well, but not so the rest of the boat. It will pivot forward over the obstruction and sometimes bounce back. The damage may not be so bad. Ask me how I know.
The other difference is that when you run hard aground on sand, I believe you will have easier time getting off without outside assistance with a fin keel boat. Fin keel boat can be usually wrenched around easier, (motor or kedge) so it points more towards the deeper water and wiggled free. Full keel boat can actually ride up on the shoal further and higher, lacking the aforementioned pivoting/pitching forward bit.

My experience was the opposite. A 42 ft fin and spade charter boat I managed hit a rock here in the PNW at 5- 5.5 knots. Lots of damage. Over $20k damage and that was in 2004 $.
Broke the engine be from the hull, some galley cabinetry also came partially loose, "smile" crack aft of the keel. The boat made it back to base but was laid up in the yard for quite a while.
A long keel distributes the forces over a much greater area along the hull, lower stress in the layup.
Incidentally I hit bottom hard 3 times in my long fin Passport 47. Once trying to get in a small harbor in the Bahamas where the boat stopped and I luckily backed off and waited for tide to raise. Once near Fort Pierce on a hard submerged object outside a marina. Each time the boat stopped dead. Damage? Nope. just ding on the keel fiberglass.

Whether long or short fin, the front of the keel hits first often and acts as the pivot point.

[seasick]

I am a traditionalist by tradition. Full keeled boats have taken me and the family safely around the world and then some.

Today I was feeding some bad weather news to my brother who is sailing a 48’ alu fin keeler from Fiji to NZ currently. “Tomorrow afternoon you can expect 25-knots SSE.”

“Great!” He replied, “We’ll eat that up with 9 to 10 knots hard on the wind.”

Getting there faster is more important when the ride is extraordinarily animated as fin keeled boats can be.

I clock 140-mile day averages in my 48’ center cockpit. Mostly while dreaming of days sailing twice that fast.

[kmacdonald]

Full keel boats went with the dinosaurs. If you really like to sail, get a fin keel performance boat. For most cruisers it's all about the destination and thet spend most of their time at the dock or on the hook. If that's you, then sailing performance doesn't matter much. If you are a sailor then it's ALL about performance and fin keels are the only way to get that, other than some multihulls.

[thomm225]

Originally Posted by kmacdonald

Full keel boats went with the dinosaurs. If you really like to sail, get a fin keel performance boat. For most cruisers it's all about the destination and thet spend most of their time at the dock or on the hook. If that's you, then sailing performance doesn't matter much. If you are a sailor then it's ALL about performance and fin keels are the only way to get that, other than some multihulls.

He wants to sail across an ocean with very little experience.

So, which type of fin keel performance boat would you suggest he get to take care of him when he's totally exhausted while trying to sail across an ocean singlehanded?


Could be an old dinosaur would be best especially since they have ......been there / done that..................and they can heave too etc

[roland stockham]

This is both personal and simple. The greatest cause of hull failures is due to damage the the keel joint or rudder. Balanced rudders and fin keels give great performance but are vulnerable. If you hit anything or ground hard you can easily wreck the boat or leave it impossible to sail. The traditional long keel integrated the keel and rudder into the structure so is many times stronger. Whether this matters to you is a personal choice that depends on where and how you sail.
My view is that fin keels and spade rudders belong on the race course and don't make good cruising boat, two demanding on the crew and uncomfortable.
I would also add that performance under sail is much more about the rig and sails than the hull. Many boats are only rigged for moderate conditions. In light airs they are under canvased and in heavy going can't set sails designed for the wind speed. Add a bowsprit with a big goaster and a staysail with a heavyweight FLAT sail and you transform things. By all means use roller furlers if you want but don't expect you furling Genoa designed to fly in 15kn to drive to windward in 25kn and a heavy sea let alone heave to in a gale. Remember boats are a team effort, hull rig and sails and they have to match.
There are few bad boats only ones being used for something they are not designed for. You would not put a Jeep on a race track or take a sports car off roading so why would you expect a boat built for round the cans racing to be a good long distance expedition boat. These days most designers aim at either the charter market or coastal daysailing with lots of accommodation for family and friends. A true cruising boat would be something like 35-45ft TWO berth, how many of those Hove you seen?
Incidentally if you like classic designs but find it cramped just get a longer boat, at anchor ther is no extra charge, the main reason modern boats are short and fat with plum stems and no bowsprit is because Marina's charge buy the foot!