## Displacement tunnel-stern seabright skiff

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• Is there an example of an Atkin powerboat of the Rescue Minor style but designed for displacement speeds? I am interested in a slightly smaller version of
Message 1 of 20 , Aug 26 10:14 AM
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Is there an example of an Atkin powerboat of the Rescue Minor style
but designed for displacement speeds? I am interested in a slightly
smaller version of River Belle that can be executed in plywood but
that is designed for efficiency at a speed/length ratio of about
1.34. Robb White has convinced me that the Rescue Minor is
surprisingly efficient, so that's a good starting point. The smallest
S/L of 1.75 that I can find is Sallie Hyde, but that design doesn't
have the tunnel stern. Rescue Minor has S/L of 3.49, and even the
larger River Belle is at S/L of 2.23.

Are there any available curves of power required as a function of
speed for a tunnel-stern seabright skiff? That might help understand
the question of an efficient S/L for this type of hull.

Ron
• I don t know if either Atkin designed a tunnel-stern Seabright skiff for lower speeds. Mrs. Atkin lurks here, and she may know if there is one, and if there
Message 2 of 20 , Sep 1, 2004
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I don't know if either Atkin designed a tunnel-stern Seabright skiff for
lower speeds. Mrs. Atkin lurks here, and she may know if there is one, and
if there are any speed/power curves in existence.

The tunnel-stern Seabright skiffs are easily driven hulls. Even though the
ones in the catalog won't be as efficient running at low speeds as a similar
design optimized for that use I don't think the difference will be enough to
worry about, unless maybe you're comtemplating electric power and need to
squeeze the most out of every electron. What sort of power are you
contemplating?

On Thu, 26 Aug 2004 17:14:39 -0000, Ron wrote:
> Is there an example of an Atkin powerboat of the Rescue Minor style
> but designed for displacement speeds? I am interested in a slightly
> smaller version of River Belle that can be executed in plywood but
> that is designed for efficiency at a speed/length ratio of about
> 1.34. Robb White has convinced me that the Rescue Minor is
> surprisingly efficient, so that's a good starting point. The smallest
> S/L of 1.75 that I can find is Sallie Hyde, but that design doesn't
> have the tunnel stern. Rescue Minor has S/L of 3.49, and even the
> larger River Belle is at S/L of 2.23.
>
> Are there any available curves of power required as a function of
> speed for a tunnel-stern seabright skiff? That might help understand
> the question of an efficient S/L for this type of hull.

--
John <jkohnen@...>
One boat just leads to another.
<John Kohnen>
• ... This may sound crazy, but I plan a single-cylinder Diesel of 6.6 to perhaps 8 hp cruising at about 3/4 max power. The background is that we have done 3
Message 3 of 20 , Sep 2, 2004
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--- In AtkinBoats@yahoogroups.com, jkohnen@b... wrote:
> squeeze the most out of every electron. What sort of power are you
> contemplating?

This may sound crazy, but I plan a single-cylinder Diesel of 6.6 to
perhaps 8 hp cruising at about 3/4 max power. The background is that
we have done 3 month-long cruises (plus some shorter trips) in our
Balboa 8.2 sailboat and had a wonderful time in the Pacific
Northwest, the upper 2/3 of the Chesapeake, and Pamlico and Albemarle
Sounds on 6.6 hp. The boat is about 26' LOD, 8'0" beam, 30" draft
board up, and 5000# or so displacement loaded. Based on these
experiences, I'd like something about the same speed, economy,
seaworthiness, and accommodations, but with significantly better
weather protection and lower clearance to poke up interesting
gunkholes above bridges. We need shallower draft (tunnel stern) to
explore shallower, less visited sounds and creeks. I'd like to ditch
much of the 2300# ballast and rigging and regain seaworthiness by
adding length and perhaps narrowing the beam. The boat has to be
trailerable because we're based in Colorado. "River Belle" is close,
but somewhat bigger and much faster and more powerful than I have in
mind. I'd prefer plywood construction and a more traditional
sheerline. I'm open to suggestions for boats or modification of my
wishes.

Ron
• How shallow a draft do you need? I know, the shallower the better, but would 2 do? Take a look at Little Silver:
Message 4 of 20 , Sep 2, 2004
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How shallow a draft do you need? I know, the shallower the better, but would
2' do? Take a look at Little Silver:

Don't let the flat bottom put you off, Wader should be quite capable in the
type of water you like to cruise in, and her draft is only 1' 5":

For really low power a sailboat hullworks pretty good. Take a look at some
of the shallow-hulled centerboard sailboats in the catalog, with an eye
towards ditching the rig and adding a motorboat style cabin and cockpit
(sorry Pat <g>). You might look at Twilight and Great Bear:

You're not crazy, going slow and easy is nice. Try to make your engine as
unobtrusive as possible with vibration damping, sound insulation and good
muffling of the exhaust. Quiet is a Good Thing in a boat. It's possible to
put up with a noisy, vibratory engine in a fast boat because you get where
you're going quick and can shut it off soon, but noise and vibration are a
pain in the neck in a slow boat where you're trying to enjoy the journey...

On Thu, 02 Sep 2004 16:00:21 -0000, Ron wrote:
> This may sound crazy, but I plan a single-cylinder Diesel of 6.6 to
> perhaps 8 hp cruising at about 3/4 max power. The background is that
> we have done 3 month-long cruises (plus some shorter trips) in our
> Balboa 8.2 sailboat and had a wonderful time
> ...
> I'd like something about the same speed, economy,
> seaworthiness, and accommodations, but with significantly better
> weather protection and lower clearance to poke up interesting
> gunkholes above bridges. We need shallower draft (tunnel stern) to
> explore shallower, less visited sounds and creeks. I'd like to ditch
> much of the 2300# ballast and rigging and regain seaworthiness by
> adding length and perhaps narrowing the beam. The boat has to be
> trailerable because we're based in Colorado. "River Belle" is close,
> but somewhat bigger and much faster and more powerful than I have in
> mind. I'd prefer plywood construction and a more traditional
> sheerline. I'm open to suggestions for boats or modification of my
> wishes.

--
John <jkohnen@...>
What is more pleasant than a friendly little yacht, a long stretch of
smooth water, a gentle breeze, the stars? <Billy Atkin>
• Ron, Doesn?t sound crazy at all. With the price of petroleum products setting records, going slow may be the way of the future. Dave Gerr, NA in NY, has
Message 5 of 20 , Sep 2, 2004
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Ron,

Doesn?t sound crazy at all. With the price of petroleum products
setting records, going slow may be the way of the future. Dave Gerr,
NA in NY, has written several articles in Boat Builder magazine about
displacement speed tunnel drive. He has designed several in the larger
sizes (45 feet or so) and he seems to think tunnel drives are
efficient at lower S/L ratios.

Pick the design you like for seaworthiness and the displacement you
need for your extended cruising. Power with 1 HP per 500 pounds
displacement (seems to be the ROT for displacement speed hulls), and
go for it! Some single cylinder diesels can vibrate too much for a
very light boat. Another ROT is too make the engine bed logs weigh at
least 20% of the engine weight (with gear).

Good Luck,

--- In AtkinBoats@yahoogroups.com, "ronschwiesow" <nanron62@m...> wrote:
> --- In AtkinBoats@yahoogroups.com, jkohnen@b... wrote:
> > squeeze the most out of every electron. What sort of power are you
> > contemplating?
>
> This may sound crazy, but I plan a single-cylinder Diesel of 6.6 to
> perhaps 8 hp cruising at about 3/4 max power. The background is that
> we have done 3 month-long cruises (plus some shorter trips) in our
> Balboa 8.2 sailboat and had a wonderful time in the Pacific
> Northwest, the upper 2/3 of the Chesapeake, and Pamlico and Albemarle
> Sounds on 6.6 hp. The boat is about 26' LOD, 8'0" beam, 30" draft
> board up, and 5000# or so displacement loaded. Based on these
> experiences, I'd like something about the same speed, economy,
> seaworthiness, and accommodations, but with significantly better
> weather protection and lower clearance to poke up interesting
> gunkholes above bridges. We need shallower draft (tunnel stern) to
> explore shallower, less visited sounds and creeks. I'd like to ditch
> much of the 2300# ballast and rigging and regain seaworthiness by
> adding length and perhaps narrowing the beam. The boat has to be
> trailerable because we're based in Colorado. "River Belle" is close,
> but somewhat bigger and much faster and more powerful than I have in
> mind. I'd prefer plywood construction and a more traditional
> sheerline. I'm open to suggestions for boats or modification of my
> wishes.
>
> Ron
• Ron, While you were cruising around Ablemarle, and Pamlico, did you make it up to Coinjock for Dinner? I took a boat from Rockport Mass. down to Fort
Message 6 of 20 , Sep 3, 2004
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Ron,

While you were cruising around Ablemarle, and Pamlico, did you make it up to Coinjock for Dinner? I took a boat from Rockport Mass. down to Fort Lauderdale. Would really like to go back and spend some more time in the ditch.

Case

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• ... Thank you very much for your good suggestions, John and Lewis. This is a helpful board. You have given me much to think about. Wader is appealing with the
Message 7 of 20 , Sep 3, 2004
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--- In AtkinBoats@yahoogroups.com, jkohnen@b... wrote:
> ...You're not crazy, going slow and easy is nice.

Thank you very much for your good suggestions, John and Lewis. This
appealing with the shallow draft and good protection for the helm.
I'll be doing comparisons and will need to order plans in a while.

Ron
• I looked at the MoToR BoatinG article about Wader last night. Nice boat! The design and Billy s prose made me want one for myself! I think Wader would be
Message 8 of 20 , Sep 5, 2004
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I looked at the MoToR BoatinG article about Wader last night. Nice boat! The
design and Billy's prose made me want one for myself! <g> I think Wader
would be just the ticket for Ron. Look at the lines, the forefoot is sharp
and extends well below the waterline -- it'd take a lot of chop to make it
pound; the bottom curves up gently to the waterline aft, making the boat
easy to drive with low power (and making it a waste of money to put a big
engine in it). The construction uses full frames and batten seams. The boat
could be built with planks and still live on a trailer, but she could also
easily be converted to plywood without changing the framing at all. The
curved tumblehome at the stern would be a challenge, but it would be a shame
to do away with it. Using batten seam plywood planks in that area, two
layers of thin plywood planks, odd shaped chunks of plywood, or "cold
molding" the sides aft out of two or three layers of thin diagonal plywood
planks are a few ways the challenge could be met. As John Atkin says, "...
in some cases the lines of a flat bottom or V-bottom hull are relatively
simple so that the builder might adapt the construction to use plywood in
sheet form. Occasionally, this will require some ingenuity."

With a little care in the construction and finish Wader would be a nice
looking boat, she'd turn heads wherever she went and most people would never
realize that underneath she's just a flat-bottom skiff. <g> Don't you dare
think about raising the cabin Ron! Five feet of headroom is plenty for
standing and pulling your pants up in the morning and the rest of the time
you'll be sitting or lying when below.

On Fri, 03 Sep 2004 15:23:29 -0000, Ron wrote:
> Thank you very much for your good suggestions, John and Lewis. This
> appealing with the shallow draft and good protection for the helm.
> I'll be doing comparisons and will need to order plans in a while.

--
John <jkohnen@...>
After all, all he did was string together a lot of old,
well-known quotations. <H. L. Mencken on Shakespeare>
• Greeting to all from Okinawa, Japan. A true island paradise. Can t believe after all the time (years) and money I ve spent looking for just the right boat and
Message 9 of 20 , Oct 14, 2004
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Greeting to all from Okinawa, Japan. A true island paradise.

Can't believe after all the time (years) and money I've spent
looking for just the right boat and I stumble on to
Atkinboatplans.com. I've always equated the Atkins with double-
enders. What a surprise.. I've been looking for a traditional style
boat be it schooner, cutter, or sloop. I found the boat, or should I
say boats, because I don't know which one I like the best. My
selections are ""America Junior", "Little Maid of Kent", and of
course "Island Princess". Schooners ever last one of them. The boat
that stirs the heart and sole of everyone, sailor or not. The
dicision is difficult because the gaff mainsail of "America Junior" I
think would look great on the other two boats. If that was the case,
the decision would be easy. "Island Princess" would win. I know the
Atkins say don't change anything in the design, but if you have a
gaff sail of equal size (to include reef points) as the current
marconi design would it work? I don't see why not. Anyone's

Arrrg....
• By the way the name is Scott.
Message 10 of 20 , Oct 14, 2004
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By the way the name is Scott.
• Welcome aboard Scott! Schooners have been switched back and forth between Marconi and gaff mainsails before. You ve got to be careful not to move the center of
Message 11 of 20 , Oct 17, 2004
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Welcome aboard Scott! Schooners have been switched back and forth between
Marconi and gaff mainsails before. You've got to be careful not to move the
center of effort of the sail plan very much, or you'll spoil the sailing
balance of the boat. Jim Michalak (rhymes with "metallic") has a good
introduction to figuring out sail areas and centers of effort here:

http://homepages.apci.net/~michalak/15jun04.htm

Of course it's more complicated with all the sails a schooner carries! <g>
Just use the working sails for the math, not the light weather stuff.

On Thu, 14 Oct 2004 15:53:16 -0000, Scott wrote:
> ...
> I've been looking for a traditional style
> boat be it schooner, cutter, or sloop. I found the boat, or should I
> say boats, because I don't know which one I like the best. My
> selections are ""America Junior", "Little Maid of Kent", and of
> course "Island Princess". Schooners ever last one of them. The boat
> that stirs the heart and sole of everyone, sailor or not. The
> dicision is difficult because the gaff mainsail of "America Junior" I
> think would look great on the other two boats. If that was the case,
> the decision would be easy. "Island Princess" would win. I know the
> Atkins say don't change anything in the design, but if you have a
> gaff sail of equal size (to include reef points) as the current
> marconi design would it work? I don't see why not. Anyone's

--
John <jkohnen@...>
One boat just leads to another.
<John Kohnen>
• John, Thanks for the link to Jim s homepage. Very informative. I would never take it upon my self to change any design for fear of botching the job. A
Message 12 of 20 , Oct 17, 2004
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John,
Thanks for the link to Jim's homepage. Very
informative. I would never take it upon my self to
change any design for fear of botching the job. A
designer I am not. Many boats out there for the
backyard builder are not proven designs. Atkins
designs are proven. That being the case I would not
change the sailplan. I am a schooner man .....

By the way I did not realize you are the same John
from "The Mother of All Maritime Links." Great site
and lots of fun and information. I use it often..

Thanks.
Scott

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• Hello Scott. I know it s not an Atkin s, but I have a free Murray Peterson 44 Schooner here. Its in need of restoration, but she has very nice traditional
Message 13 of 20 , Oct 17, 2004
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Hello Scott. I know it's not an Atkin's, but I have a free Murray
Peterson 44 Schooner here. Its in need of restoration, but she has

Let me know---I will have some pix, etc on www.classicworkboat.com

Cheers, Bruce
• Even if you re just changing the mainsail of a schooner check the center of effort. Of course if you change the mainsail to a gaff sail you re on your own and
Message 14 of 20 , Oct 17, 2004
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Even if you're just changing the mainsail of a schooner check the center of
effort. Of course if you change the mainsail to a gaff sail you're on your
own and Mrs. Atkin won't have anything to do with you any more! ;o) Getting
professional help shouldn't cost much, especially when you compare it to the
cost of building the schooner. Jay Benford used to work for the Atkins, and
is familiar with traditonal rigs. He'd be a good designer to ask for help:

http://www.benford.us/

If you had a professional draw a gaff mainsail for you Mrs. Atkin might even
forgive you! ;o)

On Sun, 17 Oct 2004 08:11:28 -0700 (PDT), Scott wrote:
>
> John,
> Thanks for the link to Jim's homepage. Very
> informative. I would never take it upon my self to
> change any design for fear of botching the job. A
> designer I am not. Many boats out there for the
> backyard builder are not proven designs. Atkins
> designs are proven. That being the case I would not
> change the sailplan. I am a schooner man .....
> ...

--
John <jkohnen@...>
There is only one honest impulse at the bottom of Puritanism, and that is
the impulse to punish the man with a superior capacity for happiness.
<H. L. Mencken>
• Thanks for the info Bruce. 43 is far to much boat for me. That s why I was so excited about finding Atkin s 30 / 36 schooners. By the way I m also in
Message 15 of 20 , Oct 17, 2004
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Thanks for the info Bruce. 43' is far to much boat
for me. That's why I was so excited about finding
Atkin's 30'/ 36' schooners.

By the way I'm also in Okinawa, Japan. Another

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• Welcome to the list, Scott. As long as the topic is current, let me add that I have put together a personal site for Atkin schooner enthusiasts called A
Message 16 of 20 , Oct 18, 2004
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Welcome to the list, Scott. As long as the topic is current, let me add that I have put together a personal site for Atkin schooner enthusiasts called "A Celebration of Atkin Schooners". It is meant to be a place where those who are interested can get information and see other people's Atkin schooners. Frankly, it's just a shameless ploy on my part to find other Atkin schooner owners to talk to.

Here is the URL:
http://www.geocities.com/wmeparker

I welcome all feedback that makes sense. The best way to leave that is via the guest book.

Best,
Bill

[Non-text portions of this message have been removed]
• Thanks for the link. I like it and can t wait for other Atkins schooner owners to send in their pictures. I added your site to my favorite site list and will
Message 17 of 20 , Oct 18, 2004
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Thanks for the link. I like it and can't wait for
other Atkins schooner owners to send in their
and will check often for updates. Thanks..

How can you not love the sight of a schooner..

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• Thanks for the link. I like it and can t wait for other Atkins schooner owners to send in their pictures. I added your site to my favorite site list and will
Message 18 of 20 , Oct 18, 2004
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Thanks for the link. I like it and can't wait for
other Atkins schooner owners to send in their
and will check often for updates. Thanks..

How can you not love the sight of a schooner..

__________________________________
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• Thanks for the link. I like it and can t wait for other Atkins schooner owners to send in their pictures. I added your site to my favorite site list and will
Message 19 of 20 , Oct 18, 2004
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Thanks for the link. I like it and can't wait for
other Atkins schooner owners to send in their
and will check often for updates. Thanks..

How can you not love the sight of a schooner..

__________________________________
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Yahoo! Mail Address AutoComplete - You start. We finish.
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• Thanks for the link. I like it and can t wait for other Atkins schooner owners to send in their pictures. I added your site to my favorite site list and will
Message 20 of 20 , Oct 18, 2004
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Thanks for the link. I like it and can't wait for
other Atkins schooner owners to send in their