Please explain the advantage of an overhang to a longer waterline?

[Dockhead]

Originally Posted by Panope

I completely agree, and if my boat had needed an extended bow roller, I would have built just what you describe.

After all, I did build a pivoting dinghy davit for the reason you mention: Cheaper marina fees:

In fairness, I have never once in 8 years of cruising my present boat in 11 countries been charger for my davits. I'm always charger for nominal length (hull length) or 54', although my LOA is 56.5' and almost 60 with anchor and davits.

[GTom]

Originally Posted by Dockhead

Optimizing hull form for marina bills is just crazy. Except maybe for boats which sit in marinas 365 days a year and don't sail.

No, optimize it for stability, accommodation and performance. Regarding these, what benefit does the long overhang brings? Larger Jib and less water resistance maybe, but all lost if not heeling extensively. BTW I'll most likely pay for a home berth where I can return.

Besides that, you might not even save LOA - see Panope's drawing.

I was talking about these two practical examples: Camper & Nicholson 43 vs Oceanis 430. Everybody chooses the design fitting his/her needs.

[Panope]

Originally Posted by Dockhead

Optimizing hull form for marina bills is just crazy. Except maybe for boats which sit in marinas 365 days a year and don't sail.

Wait! I think you just described 98% of all boats

My marina has finger slips who's lenghts vary by the 5 foot increment. Boats are not allowed to overhang the dock or fairway. Everyone pays the same price based on the length of the slip.

In my case, the pivoting davit allows me to JUST sneek into a 35 foot slip. With out it, I would pay for 40 feet no matter what.

This same facility also provides my haul-out and dry storage. All of this is charged at my 35 foot length.

Steve

[bmz]

Long overhangs are designed for one simple reason: they make faster sailboats. Everything else being equal, you want to minimize your wetted surface for light air, that means you want to shorten your water line. As we all know, for heavy air you want to maximize your water line. With long overhangs, as your boat speed approaches hull speed and and your boat settles into the trough behind the bow wave the water line increases. Long overhangs decrease the water line at low speeds to maximize light air performance, and maximizes water line length in heavy air--the best of all worlds. It is only the travel trailer mindset of modern production boatbuilders that has caused these ugly and slow designs with minimum overhangs

[Paul L]

Originally Posted by bmz

Long overhangs are designed for one simple reason: they make faster sailboats. Everything else being equal, you want to minimize your wetted surface for light air, that means you want to shorten your water line. As we all know, for heavy air you want to maximize your water line. With long overhangs, as your boat speed approaches hull speed and and your boat settles into the trough behind the bow wave the water line increases. Long overhangs decrease the water line at low speeds to maximize light air performance, and maximizes water line length in heavy air--the best of all worlds. It is only the travel trailer mindset of modern production boatbuilders that has caused these ugly and slow designs with minimum overhangs

The logic sounds good. It just doesn't hold up to reality. Take a classic long overhang design like an Alberg 35 and compare it's speeds to a J35 or a Benetau First. The newer boats are much quicker.

[bmz]

Originally Posted by Paul L

The logic sounds good. It just doesn't hold up to reality. Take a classic long overhang design like an Alberg 35 and compare it's speeds to a J35 or a Benetau First. The newer boats are much quicker.

"Everything else being equal"

[GTom]

Originally Posted by bmz

"Everything else being equal"

Once you heel for a decent LWL, you'll wet a larger surface. Otherwise why are all speed recorders nowadays gather around the Farr-design with very little overhang?

[TJ D]

Originally Posted by bmz

Long overhangs are designed for one simple reason: they make faster sailboats. Everything else being equal, you want to minimize your wetted surface for light air, that means you want to shorten your water line. As we all know, for heavy air you want to maximize your water line. With long overhangs, as your boat speed approaches hull speed and and your boat settles into the trough behind the bow wave the water line increases. Long overhangs decrease the water line at low speeds to maximize light air performance, and maximizes water line length in heavy air--the best of all worlds. It is only the travel trailer mindset of modern production boatbuilders that has caused these ugly and slow designs with minimum overhangs

If this is the case, I'm wondering why all of today's fastest designs very clearly demonstrate exactly the opposite of what you're stating here. There is a huge amount of money being thrown at achieving maximum speed under sail, and I think that you would be hard pressed to find any of these boats with the hull shape of, say, a Nicholson 43! If a boat with long overhangs was truly the fastest design, they would be dominating the race circuits. this is not happening.

[Paul L]

Originally Posted by bmz

"Everything else being equal"

So you want to compare a CCA designed boat to what? A non-existent modern design with a CCA style underbody and rig, but a longer waterline????

[bmz]

Originally Posted by TJ D

If this is the case, I'm wondering why all of today's fastest designs very clearly demonstrate exactly the opposite of what you're stating here. There is a huge amount of money being thrown at achieving maximum speed under sail, and I think that you would be hard pressed to find any of these boats with the hull shape of, say, a Nicholson 43! If a boat with long overhangs was truly the fastest design, they would be dominating the race circuits. this is not happening.

It is my belief that modern racing boats are so efficient in generating their own wind, that there is little need to minimize wetted surface for light air (not the case for for cruising boats). Moreover, traditional double water line designs are heavier for any given waterline length. Regardless, for many decades the fastest designs were built around the double waterline concept.

[bmz]

Originally Posted by Paul L

So you want to compare a CCA designed boat to what? A non-existent modern design with a CCA style underbody and rig, but a longer waterline????

A modern 35 foot boat will carry more sail, with a taller rig, and weigh less than an Alberg 35. This has nothing to do with a CCA rule, just advances in design and materials.

[Paul L]

Originally Posted by bmz

A modern 35 foot boat will carry more sail, with a taller rig, and weigh less than an Alberg 35. This has nothing to do with a CCA rule, just advances in design and materials.

The long overhangs were typical of the CCA rule boats, that's why I mentioned it. My Alberg 35 weighed close to the same as my J/37.

[thomm225]

Some of us simply like the look and advantages of the long overhangs even after owning fast racing boats with plumb bows and sterns.

Lots of sailboat designers use models in tanks during the design process.

I got to witness this model thing first hand while racing beach cats. We were coming through Pensacola Pass and the waves were 6' plus going thru the pass and steep but the wind was dying.

We on our super fast new Nacra 6.0's (this was 1997) were slamming off each wave as it passed. We were way ahead of the Hobie 16's at this point but got to see them with their rocker bows and sterns come thru these same waves on our way back in from the Seabuoy 3 miles offshore.

They practically glided through them! They went through so smoothly it was amazing but they were built for the surf.

As far as monohulls, the old style boats with overhangs, especially the smaller ones, give you much needed space.

I have a 16'6" kayak on the deck of my boat which has a LWL of 19.75' and a LOA of 27.16'

I have maybe 40' of heavy chain, 20 lb CQR, 3/8 shackles, and a 22 gallon water tank in the bow as well.

Without the overhangs this boat couldn't do the things it does or carry what it can carry on top of that it's great when the wind and waves get up a bit

[Paul L]

I don't understand the argument that long overhangs gives you much needed space. It seems like you want to make the comparison based on LOD. To me a better comparison is what size slip does it fit in, aka LOA.

[thomm225]

Originally Posted by Paul L

I don't understand the argument that long overhangs gives you much needed space. It seems like you want to make the comparison based on LOD. To me a better comparison is what size slip does it fit in, aka LOA.

My point on this was the kayak.

My kayak is 16'6" and with a boat with say a 20' LOA and 20' LWL the kayak would be extending into the cockpit area whereas on my boat I have my cockpit totally clear

The other part is the anchor, chain, water tank etc..............and a larger V berth

On top of that, many of us just like the history and attempting to relive it rather than sailing some sort of floating condo