One of the more evident features of testing the models I used is that the directional stability, and by this I mean the inherent ability of the boat to keep to a course ie a straight line, when pushed or pulled through the water, is superb compared to the conventional situation when the front is the sharp end.
The reason for this at least twofold. In the first instance in any forward motion a sharp edge engages instantly on the conditions immediately - these will be conditions in the water and air combined but allowing that a hooly is not blowing and creating waves to hit and bias the transit of the bow through the water, it will be the underwater form, presence of any keel like structure and the draught of the boat. Secondly as a result the pressure differences in the water on each side of the bow will tend to deflect instantly and the bow waves that are thus created as direction of the craft changes, are, at the instant they are generated, equal but as the change in direction occurs the wave form generated on the opposite side to the new direction of travel, should stop that change in direction and oppose the change. But this doesn't happen. The vertical axial plane through the lubber line changes as and because the craft leans over out and away from the new direction (like a car going around a corner as opposed to a motor bike) and offers more of the craft's leading surface on that side and this and that the already generated bow wave further enables the change in direction. Effectively it will exaggerate the change - not too good if one is trying to keep a straight line in very bad conditions.
Where the front is bulbous or rounded but not bluntly square on, an area of raised pressure at the waters surface ( and in the air above ) is generated with forward movement of the craft and stays with the craft till it is dissipated at the maximum width of the craft and then provides, at least theoretically a moment or pressure gradient to squidge the craft forward. On the side to which the craft is turning the pressure wave sidles paste the point of maximum beam, which is well forward and creates a relative negative pressure effect on that side which will pull the hull to the opposite side and cause the hull to come back away from the direction of the turn.
