T.R | Title | User | Personal Name | Date | Lines |
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303.1 | | GRAMPS::WCLARK | Walt Clark | Tue May 13 1986 15:59 | 37 |
| The shallow draft boat compensates for the fact that the ballast
is not carried as low by increasing the ballast. The ballast is
usually concentrated in a fat lump which has very little lateral
resistance and reduces upwind performance (leeway, not necessarily
heeling - which is compensated for by additional weight). A shallow
keel with a centerboard can allow you to get some of the lost
performance back. A ballast to displacement of 40-45% seems normal,
but you cannot tell how stiff a boat will be from this alone. Depth
of the ballast, hull shape, size and height of the sail rig and rudder
location, size and type all contribute to the sense of 'stiff' or
'tender'.
My first keel boat had a deep fin and B/D of 50%, a Vee shaped hull,
spade rudder and generous sail plan. She would heel heel to 40
degrees and track like a freight train. I still dont know how to
classify her. My wife considered her tender (not to mention
inconvienient) cause she had to move about. Since I was on the
helm 95% of the time, and that was no work once you propped yourself
up, I thought she was pretty stiff (at 40 degrees heel).
Maybe I am not the norm, but I find the bay keeps the Sailing
Dictionary definition of destination fresh in our minds. We seem
to be always going to weather.
My present boat has a Scheel (patented) keel (a cross between shoal
draft and a winged keel) that I feel provides very good performance
and saves about 18" draft. Neither Catalina or Pearson offer this option.
For the bay, I would want to keep my draft under 5' if practicle
and certainly under 6'. The draft doesnt affect sailing areas too
much, but access to and space in the coves improve quite a bit
every time you chop a foot from your draft.
I hope more info helps rather than confuses the issue for you.
Walt
anchorage.
|
303.2 | so what's a foot? | PULSAR::BERENS | Alan Berens | Tue May 13 1986 16:52 | 17 |
| "..... but access to and space in the coves improve quite a
bit every time you chop a foot from your draft."
Hmmm, I've always wondered about this argument. Perhaps it is because we
sail in rocky places like Maine, but we are always careful to keep at
least 10 feet under the keel. Bashing into a ledge or boulder can do a
lot of damage, especially to a centerboarder or to a boat with the
ballast encapsulated in fiberglass. Where there is a large tidal range
(10 to 20 feet down East) a foot of draft more or less is really
irrelevant. I'd opt for the better sailing performance of the deeper
keel. The PHRF ratings for the shoal draft versions of most production
boats are many seconds per mile higher. Of course, if you only sail over
sandy bottoms in calm weather at low tide .....
Alan
|
303.3 | | GRAMPS::WCLARK | Walt Clark | Tue May 13 1986 17:43 | 41 |
| Well Alan, Narrangansett bay has maybe 5 rocks. There huge shoal
areas with soft bottoms that change very gradually and can be sailed
if you have some experience there. One in particular I can think
of is a section of Narrangansett Bey called Greenwich Bay. A lot of
boats either sail this bay or transit out to other areas from marinas
at the west end.
This bay has very large areas 3-6 feet deep along the northwestern
perimeter into Apponaug Cove and the southeast edge into Narrangansett
Bay. A shallow draft boat can cut an hour off a sail from E. Greenwich
to Newport just by being able to cross the 5' bottom shallows instead of
rounding the buoys.
Good coves like Potter's and the Kickamuit (technically a river
I guess) have lots of space near shore where the depth is under
6' but limited anchorage in 8-12' water due to crowds and morrings.
At Dutch Island Harbor, you have to get there early to anchor
close to shore in 8-12' depths, but if you can stand 5-6' of water
under you there is lots of space close in.
If the justification for shallow draft was simply to avoid rocks,
I would agree that the foot wont improve the odds of missing one
much (I used to sail the Conn. side of LI Sound, so I have some first
hand experience with submerged rocks).
Looking back a the keel depths of the Pearson and Catalina refered
to in .0, I would say that the savings of 6-10" isnt worth much
given that they are all under 5' anyway. So given 'my' critera of
<5' being desired, either option meets the goal. In that case,
the performance advantage of the slightly deeper keel would out
weigh the added draft savings.
Of course there is always those Eddy & Duff boats that sail in wet
grass. That would be the next level below 5' that would open new
Narrangansett Bay horizons. There are at least as many coves that have
no more than 3' of water at low tide as have >6'. Swimming might
get sticky, but at least there wouldnt be any power boaters to keep
you up all nite.
Walt
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303.4 | | PULSAR::BERENS | Alan Berens | Tue May 13 1986 18:30 | 15 |
| Oh well, I've never sailed in Narragensett Bay (except once as crew). My
education does have its gaps.
Indirectly, you've made the important point that one's choice of a boat
is greatly influenced by the waters one sails in and by one's sailing
interests. Perhaps those asking for and giving advice should indicate
their biases (though the biases of us advice givers tend to be obvious
after a while, I suppose).
By the way, if you like anchoring in these shallow spots, have you
considered a twin bilge keel boat? This might open vast new anchoring
areas, and, in fact, at low tide you needn't even worry about the
anchor. You just step over the side and go clamming!
|
303.5 | one opinion | RDF::RDF | Rick Fricchione | Fri May 16 1986 12:23 | 21 |
| Perhaps mentioned by Walts note, but I chartered a shoal draft boat
recently (an Irwin) and was extremely disappointed with how it sailed.
As the breeze began to stiffen up, the boat began to slip sideways
more and more. She would not track well at all. Sail it first
and see if it performs to your expectations. In Narraganset bay
you are usually beating to the south into Newport, and running or
a beam reach back up the bay in the late afternoon. I'd worry
about it going to weather well.
With regards to getting in close to shore in a shoal draft, I agree
with Alan. I've never taken my boat into waters that shallow for
reasons ranging from submerged rocks to hungry bugs. It may save
you time cutting buoys out of Greenwich Bay, but I'd worry about
being able to do that next year, or the year after. They're not
guaranteed to be clear the way a channel is. Its a gamble, nothing
less. I'd rather just plan in the few more minutes.
Rick
|
303.6 | Price of shoal vs deep | BPOV09::TMOORE | | Mon May 19 1986 13:48 | 13 |
| What I haven't seen here (and it may not be an issue) is price and
availability of shoal draft verses deep draft. The last time I
was in the boat buying mood it appeared (not a marketing study)
that there were more shoal draft keel baots around and the price
was less than the deep keeled boats.
comments please!
tom
|
303.7 | More lbs = more $$ | SUMMIT::THOMAS | Ed Thomas | Mon May 19 1986 14:17 | 7 |
| I have a problem with the cost of a shoal draft keel being less
than a deep draft version. Generally, the shoal draft keels are
heavier than deep draft which should require more ballast (hopefully
lead) to figure into the total cost of the boat.
Ed
|