|
IMB, SAIL BEACHBOAT, 13-1/2' X 5-1/2',
350 POUNDS EMPTY

IMB features a "Birdwatcher"
cabin, full length with panoramic windows and a center
walkway slot in the roof. Everyone rides inside. This
style of boat was invented by Phil Bolger in the early
1980's.
These boats can be self righting with
minimal, or no, ballast because crew weight works as ballast.
They sit low looking out through the windows (although
standing in normal winds is quite acceptable). The cabin
sides provide lots of buoyancy up high to ensure a good
range of stability. IMB, which is small with a light bottom,
should reliably self right from 60 or 70 degrees and in
the test described above self righted from a full 90 degrees
of roll.
These boats are operated from within
the cabin, like an automobile. No one need ever go on
deck. For boating with children I can see no equal.
These are usually cool inside. The tinted
windows cut the sun's power. The crew can sit in the shade
of the deck. Downdraft from the sail cascades through
the walkway. (By the way, at the Conroe messabout two
boaters with Lexan windows noted that mosquito spray will
ruin Lexan with one application and they noted belatedly
that the back of the spray can says so.)

IMB has an 8' long cabin on a multichine
pram hull. The prototype was built to perfection by Gerry
Scott of Cleveland, Texas. At the Conroe (Houston) messabout
I got a chance to look over his boat plus the only other
IMB I know of built by Bob Williams. Both boats were quite
true to the plans. Both had added low inside seats which
made them more pleasant to use to the point that I will
show some seats on the plans. I was worried when I drew
IMB that the headroom would be minimal so drew no seats
thinking the crew would sit on the floor, as with the
original Birdwatcher. While I was sailing with Gerry,
Bob's boat came out on the lake with four adult males
and no sign of bogging down, showing that these fat pram
shapes, very much like my Piccup Pram, can handle a lot
of weight in the 13.5' length. Here are three of the pirates
plus another who was taking the picture.

Later they took on a
mermaid and returned to the dock with five.

I don't know if either boat had ever
been weighed and the 350 pounds I quote as the empty weight
is just a guess. One of the ideas behind the boat was
that it might be towed behind a compact car and I was
glad to see that Gerry tows his behind a 1500cc mini SUV.
Both men adjust well to the lug sail/leeboard
rig. Gerry's has the blueprint 104 square foot sail and
Bob's uses the 114 square foot Bolger Windsprint sail
available from Payson. I used to worry a bit about running
a leeboard on a full cabin boat like this since handling
must be done by remote control, so to speak. No problem.
Both boats have the leeboard lanyard running to a cleat
on the aft deck. The leeboard position is plainly in view
at all times through the cabin window. In use these leeboards
need only lanyards to pull them down. Once down they will
usually stay down until they strike something. Then they
pop up and you will need to pull them down again. I've
never seen a need for a lanyard to pull the board up although
I've seen several rigged that way. The Dovekie design
had elaborate cam operated levers in the cabin that operated
the leeboards and I thought that all very clever. But
in talking to some Dovekie owners I found the internal
levers are not universally loved since they can often
be in the way. Anyway, my idea was not to run the down
lanyard to the aft deck but rather through a small hole
in the side of the boat, say 1/2" for a 1/4"
lanyard, so it could be operated totally from inside the
cabin.

Both Gerry's and Bob's boats used electric
trolling motors. The plans show rowing ports and no provisions
for a motor. A boat like this won't be a fast row boat
but it might be useful in a calm. Even the 24' Birdwatcher
would row about 2.5mph in a calm. But I'll admit that
adding a motor to Birdwatcher makes it a much more useful
thing.
IMB takes two sheets of 1/2" plywood,
eight sheets of 1/4" plywood and one sheet of 3/16"
Plexiglass. Taped seam construction using no jigs or lofting.
|