Fat Stern Boats

[Zednotzee]

Originally Posted by Don Lucas

I haven't see Bob Perry post in a while.

He could be busy- he's been writing a series of articles on boat design for Good Old Boat magazine.

[TaoJones]

Okay, here's the one I was remembering - check out this thread, starting with Bob Perry's answer at #25:

http://www.cruisersforum.com/forums/...tml#post233850

TaoJones

[RainDog]

Seems like there are two conversations here:

1) Stern shape - canoe vs. rounded vs. …
2) Boats with wide, flat aft sections vs. boats with more moderate beam aft

Seems like the early posts were #2 and the later post switched to #1. They are completely different and IMHO unrelated conversions. To me #2 is a more interesting question.

It seems like flat, wide bottoms encourage plaining and allow you to fly more sail. None of that means they sail better. Just that they are faster when sailed by professionals. If they could get an extra knot while sacrificing 90% of their safety they would in a heartbeat. That does not mean it is a good choice for a cruiser. Also since they increase wetted surface, they are slower unless you are using that to fly a lot of sail, which the racers do, but the cruisers not necessarily.

For certain the flat, beamy aft sections increase the space in the cockpit and down below. That is why most (but certainly not all) modern production boats have wide back ends. Most people really do not care how well they sail. They just want two private cabins in the back.

[S&S]

Originally Posted by RainDog

For certain the flat, beamy aft sections increase the space in the cockpit and down below. That is why most (but certainly not all) modern production boats have wide back ends. Most people really do not care how well they sail. They just want two private cabins in the back.

I'll bet you have the answer right there.

[stevemac00]

I've owned a Hunter and Beneteau. The Beneteau was a recent typical beamy stern. In waves she got knocked around quite a bit and was a struggle to keep on course as the wheel autopilot couldn't begin to handle the load. She was like a roller coaster on bow waves. Not a comfortable ride in rough weather. Still, at the time it was the best boat for us and under the circumstances I'd buy it again (we lived on it with two teenagers) but I never felt safe in rough waves.

But I'm been a field engineer now for 30 years and I fully understand that is a world difference between atheory nd realilty sometimes...

'

I'm an engineer and it's not theory so much as physics.

[DaveOnCudjoe]

My Sea Pearl is double ended and I like the design and feel of the boat. I also compete with modern full stern designs in challenging conditions and am routinely bested, I suspect mostly because the skipper is my superior. However, I have had this discussion numerous times and it is explained to me that the full transom must be ballanced by bouancy in the bows. If one visualizes the axis of rotation when loaded aloft it tendes to make sense. I'm told that if moderately ballasted they surf better and plane in certain conditions. Dave

[Pete7]

Since most of a canoe stern is out of the water unless you have the thing cranked right, over does it make any difference?

Two photos, one an HC 33 mentioned in one of the linked threads and ours. Ignoring the keels for the moment, the under water shape doesn't look that different or does it? If you drew another 3 feet on hours with some curves would you end up with a canoe stern?

How do we handle in big following seas, well sadly or fortunately depending how you look at it, we haven't found out yet despite owning her for 3 years. We normally have to deal with short steep waves caused by wind over strong tial conditions which are completely different.

Pete

[stevemac00]

Your Moody is not as beamy in the stern. Here's a comparison of a Beneteau 39 and PSC 37.

[MarkJ]

Its really hot here today (and the last few days)


really hot.

We have been sitting on the swim platform with out tootsies in the water.


Ahhhhhh...............

[Pete7]

Now your just rubbing it in. Haven't you got some teak decks to scrub or varnish to sand.

Oh and there is a plague of jelly fish in Europe this year, global warming apparently

Steve, yes take your point we are a more pointy than some of the later French / German designs with twin rear cabins.

Just been looking at the Hans Christian 33. What an interesting layout sorry bit of a thread drift.

Pete

[stevemac00]

As Turkey Cruiser pointed out there's a choice to be made. I really miss my Beneteau walk-thru with swim platform but I think the original poster's question was "How do the fat stern production boats handle in moderate to rough seas?".

[s/y spindrift]

According to Perry;" Transoms;"
" Light , beamy racing boats with shallow hulls can get away with wide sterns because when they heel, they present narrow heeled waterlines to the waves... these boats have huge rigs and horsepower to drive their hulls despite drag"
" The family cruisers mass produced..... such as Hunter and Beneteau employ a wide stern for interior volume. Some might argue they are fast because they resemble racing boat sterns, but it doesn't work that way...you do not want the corner of a cruisers transom dragging when it heels because that produces drag"
" Making a cruiser fat aft can also create helm balance problems" ( weather helm) However, "boat buyers love volume"
All yachts are a compromise. Of course you can dip your tootsies in the water, it just takes a little longer to get there!