The #1 Dealer for Hanse Group:
Hanse, Dehler, RYCK
North American Dealer:
MAT / Mills Design
#1 Dealer for Sabre Yachts
Marblehead, MA: 603-867-3130
South Dartmouth, MA: 508-596-1495

Bump's World


Bump's World - June 2022
June 2, 2022

Sex Standing Up In a Canoe

If you have ever tried having sex standing up in a canoe, you noticed it was very tippy. You probably did not notice that the hull tipped uniformly?

Hull forms and boat designs go back hundreds of thousands of years. If you look at many very old designs, like canoes and Egyptian galleons, you will notice how symmetrical they were. This is because they did not want the boats to have a bow down tendency; the symmetrical shape created more buoyancy in the stern than in the bow. Today some boats have a bow down tendency which increases the drag and makes the boat wetter.

People often ask me what the best material to make a boat out of and I say the answer is simple, wood. You have never seen a fiberglass boat over 100 years old, right?

So not only did we need a symmetrical hull shape, we needed it to be strong and since we were using wood, we built a stem, planking, and frames. This works very well in wood construction, and this likens the canoe form. This creates a Vee shaped hull which cuts thru the water nicely. The keel was attached on the full length of the stem so that structurally the hull can support the keel. Also it was hard to go deep with the keel so they went long. Deep put way too much load on a small area, and the hull could not do that.

Again, for hundreds of thousands of years, boat building did not actually change very much. Ok you can point out Donald McCay and his Clipper Ships which were a huge improvement but still is a canoe body.

In the 1960s along came fiberglass. The original fiberglass boats were just wooden hull shapes built out of fiberglass. Canoe shaped, full keel, and ribs made out of fiberglass. They also had no idea how strong fiberglass was or how long it might last in water. It was not that expensive so they used lots of it. The early fiberglass boats were not lighter than the wooden ones.

Look at most boats built in the 1970s thru mid 1980s. Turn them over and they look like a canoe. The pinch on both ends made them squirrely down wind and only aloud for small cockpits and no aft cabins.

To make a new design we had to carve a wooden model and drag it back and forth in a tank. If we wanted to change something we had to carve a new model. This took a lot of time.

The mid 80s was the beginning of computer designs. Some of the first computer designs had some really bad issues but they got better quickly.

Now we could design a boat on the computer and make small changes and see in short time how that affected the sailing characteristics. No more carving wooden models. Computers created VP (Velocity Prediction) charts that show how the boat speeds up or slows down with the changes. However sailboat races are not won on computers. Real yacht designers make the difference.

The energy of the sailboat is created by the power of the sail plan. The balance is controlled by the location of the keel. Now we can increase the width of the stern and by controlling the location of the keel and the sail plan, we keep the boat from having a bow down tendency.

This opened up the cockpit and made for fat rear ended boats, and big aft cabins, maybe even twin aft cabins. We also see twin steering wheels.

In yacht design, up to this point most of the stability came from the keel. Now we are able to create stability from the hull form. The hulls are no longer narrow Vee shaped but rather U shaped. This creates way more interior volume and a lot of stability, especially down wind. The old broaching machines are fading away. The U shaped hull also has a much lower drag coefficient so the boats are much faster up and down wind.

Having a much better idea of what fiberglass can do, the boats have an inner grid frame, gone are all the ribs. Fiberglass boats today are not just wooden boats made out of fiberglass.

There also appears to be no time limit to fiberglass boats. Older boats hold together just fine.

Unlike the medieval barber, things have advanced and gotten a lot better. Boats are stiffer, faster and way roomier.

So the next time you are standing up in a canoe having sex, remember it's really tippy. You are probably going for a swim.

Please mail comments to me at

Bump Wilcox