The Online Magazine For Amateur Boat Builders














The Magic Monkey Stick
by Greg Grundtisch
excerpted from "Messing About In Boats"

Did you ever wonder what that little scale was for on boat building plans? The one with the "V" in it and no numbers? For most amateur builders, and even some highly trained pros, this item is a mystery. Yes, it is a scale, but the beauly of it lakes a little explanation. So does the nautical term "Magic Monkey Stick."

While trying to draw the shape of Dreamcatcher's transom on construction paper, I was having difficulty finding all the heights and half breaths from the table of offsets or anywhere else on the plans. They just weren't there. Or so it seemed. I asked Mr. Tom Gruenauer, one of the finest boat builders and restorers in my area, for help getting out the correct shape. He was the one who asked me if I knew what that "thing" is on the plans. I said no. but handed him a book by Greg Rossel entitled Building Small Boats. I was using it to help with the table of offsets and noticed a photo and explanation of the scale thing. He read the couple of paragraphs and then asked for a stick with a straight edge. A small one. With a big smile and a look like he was revealing the secret of the pyramids, he went to the drawing of the transom and then to the scale and said, 'This is great, look!" He then proceeded to show me how it worked.

Somehow, over the course of the evening I was calling it the magic stick, then the monkey slick, and then it somehow became the "Magic Monkey Stick." The term is now in the local boat building lexicon.

Here is how it works. Take a stick, straight edge, or strip of paper, go to the drawing and mark ANY part, piece, section, height, length, etc. Mark both ends on the stick and go to the scale. The "V" in the first box is divided into 12 segments for inches. Take the marked stick and place it on the scale so that the mark on the right aligns with the largest whole inch line (scale foot) and the mark on the left falls in the "V" section. Slide the stick up or down until this mark hits on the "V"
line. Count the number of segments and then add the whole number. That is your measurement. This is only to the inch.

I don't know if this is a big revelation to many, but I have looked at a half dozen boat building books and none have any explanation of this scale except Greg Rossel's. Now before you say that you can simply use a scale ruler, wait. The advantage is that this can be used where the ruler cannot. If you happen to he looking at plans that have been reduced from the scale drawings, say in a fine magazine such as this one, or a book, or wherever you happen to find one, the scale on the paper is reduced equally along with the drawing. A scale ruler wouldn't work, the stick will.

It's magic!