PDRacer Sailboat - Other Variants

Official "Duck Related Variant" or "Duck Cousin"
or "Scaled Duck" (or whatever you want to call them)

Duckling
2' wide 6' long using a scaled shrink, all stations are 9" apart and 75% of what a full size would be.
Duckling 1 Lucy Ceaglske un-named
Duckling 2 Emma Ceaglske un-named
Duckling 3 Bryce Lanhart un-named
Duckling 4 Sam Peckels un-named

Skinny PD
Same PD side panels and rules, only difference is that the hull is skinny like a kayak. For sailing or paddling etc.
#01 David "Shorty" Routh - Phoenix AZ "Romana"
#02 Ken Ceaglske "Cootie Chaser"
#03 Clint Davis - Newnan, GA unnamed
#04 Tammy Ceaglske "Simplicity"
#05 Mike Parson un-named
#06 Doug Goodsell "Pirate Duck"
#07 Jack Lanhart un-named

Beer Duck
A minature PD which is towed, to carry your beer cooler and other supplies.
un-named by Phil Keck

Paddle Duck
24" wide x 8' long -- Half of a full PDRacer, a 2nd one can be made and joined with it to make a class legal boat.
un-named by Bill Buckley of Iowa.

Kayak Duck
30" wide x 8' long -- Narrow and short PD, used as a kayak. An 18" hull could be added to the side to make it class legal for racing.
"Sail Fish" by Ellen Sheets of Gahana OH.

Crabbing Duck
40" wide x 8' long -- For use to go crab fisihing, and tend crab pots. Also easier to stick in trunk / hatch of a car.
"Crab Whisperer" by Billy

PD Cruiser
50" wide x 10' long -- A PD that is stretched to 10' long.
#01 Denny un-named

Puddle Goose
48" wide x 12' long -- A PD that is stretched to 12' long.
#01 Katie & Bob Alston "Katies Puddle Goose"
#02 David "Shorty" Routh "Ice Burgers" website

Variation Qualifiers
When designing and building your own boat, there are almost endless possibilities and compromises. A number of people have expressed the desire to build a variation of the pdracer (such as a stretched version), yet keep it part of the pdracer family. Here is the definition of what would be considered a pdracer variation.
NOTE: The variations won't be class legal for racing with the original pdracer - but it would be perfectly OK to race the variants against each other.

1 - Must use the existing rocker definition, in some scaled form (can stretch or shrink, but can't change the proportions between the measurements).
2 - Has to have flat parallel sides (like the PD, no curved sides)
3 - To name the new variation, and declare it's existance, you have to build a hull and make it go 3d. Anyone can draw on paper, it takes guts to start building. (ironically though, the building often takes less time than the drawing).

Q - do I have to keep the same beam to length ratio?
A - No, you just have to keep the same proportions between station marks, and proportions of depth. Example: If you wanted to make a 12' long boat, you would have 18" inbetween the marks, instead of the 12" that is specified.

Q - Do I have to keep the same bow angle?
A - No, when you stretch or shorten the hull, it really messes up the bow angle, so you can use whatever bow angle looks right

Q - Can we add a little curvature to the sides?
A - No, if you do, it will make it some other type of boat, and beyond what we would consider a PD variant.

Some Ideas:
6' long x 30" wide for a kayak
12' long x 4' wide for a family daysailor
16' long x 40" with wings for a skimmer board boat
16' long x 5' wide with a cabin for a pocket cruiser
2 of 14' long hulls for a catamaran, such as: idea 1
Andrew Linn created a drawing of 1/2 and 3/4 scale sizes: [click here]

Designing Other Hulls
Box hulls with flat sides are very easy to design with. To calculate how much each hull will carry, all you need to know is the square area of the rocker shape on the side of the hull. Water weighs 62 lbs per cubic foot, so if you know how much space the rocker shape takes up (displaces), then you know how much weight that shape can carry.

Hull Length in Feet	6'	7'	8'	9'	10'	11'	12'	14'	16'
Hull Length In Inches	72	84	96	108	120	132	144	168	192
Inches Between Station Marks	9	7	12	13.5	15	16.5	18	21	24
Square Area Rocker Shape (with both transoms touching the water)	232	301	366	444	504	575	647	790	933
Max Weight Can Carry with 48" Beam	399	518	630	764	868	990	1114	1360	1606

Lets calculate how much a stock PDRacer will carry as an example. The hull is 8' long, so looking at the table the rocker shape is 366". The hull will be 48" wide:

366" rocker shape area
x 48" wide
-------
17568 cubic inches total displacement

Now, we know that there area 1728 cubic inches in every cubic foot.
17568 cubic inches total displacement
/ 1728
-------
10.16 cubic feet

So now we know how many cubic feet the hull will displace. Water weighs 62 lbs per cubic feet, so multiply by that:
10.16 cubic feet
x 62
-------
630.3 total displacement of rocker shape

Presto, we know that a PDRacer can carry 630 lbs with it's rocker shape. Don't forget that the shape has to carry the weight of the boat too, so add that in when calculating everything that the boat will need to carry.

The PDRacer was designed with the maximum rocker a bit far back for a number of reasons. The crew weight is likely to be a significant factor, so you will probably have to sit on the "flat spot" area of the hull.

Calculate Boat Weight
One method to figure out how much your boat will weigh is to make a spreadsheet that lists every part that makes up the boat, and their volume. Then multiply that volume by 37 lbs per cubic foot, that is a rough weight of Southern Yellow Pine, a common cheap wood. Here is the spreadsheet I used when guestimating the PDRacer, I only listed a couple of 2x4's because I knew from previous boats that is how many I would need. You migth want to list every individual framing piece instead for a more accurate number. Don't forget to include the mast and spars.

piece	x	y	z	area (cubic foot)	weight (per cubic foot)	piece weighs
bottom	48	96	0.38	1.00	37	37
side	18	96	0.25	0.25	37	9
side	18	96	0.25	0.25	37	9
bow deck	12	48	0.25	0.08	37	3
bow bulkhead	12	48	0.25	0.08	37	3
stern bulkhead	18	48	0.25	0.13	37	5
stern deck	18	48	0.25	0.13	37	5
2x4x12	1.5	3.5	144.00	0.44	37	16
2x4x12	1.5	3.5	144.00	0.44	37	16
2x4x8	1.5	3.5	96.00	0.29	37	11
					Total	114

Why The Limit On Rocker Shape?
People new to boat building are often introduced to simple hull shapes like the PDRacer first. Later when they start studying other shapes they refer to them in reference to what they know, such as saying "hey, an optimist pram is just a PDRacer with curved sides". Then later progress to saying "An AF3 is just a PDRacer with curved sides and a pointed bow". So logically you could then extrapolate that "The Titanic is just a PDRacer that is a lot bigger". :)

After you get used to the boat building vocabulary, you will realize that a PDRacer is actually one of many "box boats" and the only thing that makes it unique is the shape of the rocker. The most famous box boat is the Brick and Tortoise, but there are many others dating back for years and years. The oldest refrence to a box boat that we have been able to find so far is a "Three Dollar Scow", featured in Scientific American Supplement June 17, 1876. See Craig O'Donnell's Cheap Pages for the article. Also see his website for lots of other great cheap ideas.

So if you would like to design a hull and call it a puddle duck, it has to have a scaled version of our rocker shape. If you draw up another rocker shape, then it becomes something else.

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