the boat ski is a shock absorbing system invented by spede pasanen for the bow of a small motorboat with a powerful outboard motor. its functioning principle is damping the chopping motion of the boats bow with a ski-like device attached to the bow through a car shock absorber. when a small boat is equipped with a powerful motor, the attendant thrust will generally be sufficient to lift most of the hull above the water's surface and even minimal waves will often cause a harmonically amplified chopping motion of the bow. this represents a significant obstacle to the forward motion of the boat, but is also part and parcel of the image many boat buyers aspire to, when choosing the particular configuration. a boat equipped with a boat ski will move much more smoothly, swiftly and fuel efficiently, but looks slightly ridiculous, and not at all in accord with the image the majority of buyers were looking for when plumping for a light hull and overpowered motor, instead of more steady alternatives. as was characteristic of many other of spede pasanen's inventions, the functioning of the invention was immaculate, but imagewise, it was less than plausible. thus it tended to be utilized by serious boat owners (including those who use a boat in a professional capacity), but not the wider market. 
Marine_propulsion