There is but one skeg on a "regular" boat. We chose to double it to let you pull the boat easily on shore. Indeed, when you are not alone, it's easy to carry Arwen's 30 kg. But when you have no help, you'll want to pull it on its skegs, while lifting only the bow. This will be easily done with one hand on the breasthook, and the boat will slide quietly balanced on these "skids".

The advantage of the twin skegs is that they provide 2 support points, instead of the single skeg on which the boat will pivot to bounce on one bilge and then on the next while twisting your hand until you surrender to foul language, unless you put all your attention to keeping the boat upright and none to choosing your path.... Furthermore, the weight of the boat is then divided by 2 at the friction points, which you'll enjoy most on sticky mud or soft sand!

It is true that duplicating the skegs also increases wetted surface. When on the water, you'll find the added drag negligible compared to the improvement in directional stability.

The idea of the twin skegs came to me by looking at the hull of the "cobles", fishing vessels of the shore around Hull, on the north-eastern coast of England. Because of the lack of natural havens on this coast, the boats have always been stored clear out of water when not out fishing. Each time they go out to sea, they have to be drawn down the beach on rollers, and back up again when returning from a fishing trip. This practice is still in use today, except that tractors have replaced animal or human power for the handling operations of the boats. The hull shape of the cobles is the result of specialization in response to the necessity of going in and out of the water easily: the hull has very little draft because waters are shallow on these long beaches, and it has neither keel nor centerboard, which is compensated by a deep sharp bow, supplemented as soon as the bottom allows it with a narrow and deep rudder sharply raking forward, at the same angle as the transom on which it hinges.

The nessecity to launch or retrieve the coble in the surf led to strengthening the bow. It is indeed natural to launch bow first, whereas the beaching manoeuvre is surprising: as soon as the helmsman of a retruning boat feels the first touch on the bottom, he starts a 180° turn and lets the boat back up to shore, pushed by the surf transom to the beach and bow to the waves. This way, the waves will break on the most defended part of the boat while the risk of swamping is very diminished.

But I keep the most interesting for the end: for handling on shore the deep bow had to be balanced laterally to provide stability to this hull, because it it has to be brought from the top of the beach down to the sea, which can be a long way at low tide on a flat beach. This is how the coble's characteristic twin skids came about. They are solidly strengthened by iron bands because their function is limited to shore, they have very little use in the lateral plane of the sailing hull. The flat bottom became concave with the coming of the propeller and the need to preserve a shallow draft: lifting the bottom made room for a tunnel in which the propeller remains effective when the coble is touching bottom.