displacement steel motor

[ken price]

hi,
can anyone tell me what is a displacement boat ?
thanking you,, ken price

[asathor]

Physics 101: the weight of the boat with its equipment "push aside" (displace) an amount of water of equal mass/weight (enough detail).

A boat which is said to have a "displacement hull" usually does not rise out of the water when under way. Some sailboats and heavy powerboats are semi-displacement/semi-planing, they rise up out of the water and therefor see less resistance and go faster. Planing hulls usually touch the water with a very small portion of the hull (pad) when up on a plane - small race boats sometimes less than a square foot (says my racing buddy).

Do not through you "displacement steel motor" in the water - it is undoubtedly to "dense" to float.

[ken price]

thanks for the info

[PAR]

Basically it boils down to power. All objects being propelled through the water create a wave train (series of waves) and some boats (regardless of propulsion method) haven't enough energy or power to over come this wave train. This is a function of available power and hull shape. Some shapes (hull form) require so much power, that they are limited to a theoretical speed, governed by the waterline length. Other shapes could be forced into a planning or semi planning mode, but lack power. Usually, it's a combination of both.

Overtaking this wave train is the point a displacement craft becomes partly or fully on plane. As additional power is applied, quite literally the bow rises up, as it climbs over the bow wave. The bow wave moves aft, the more power applied the farther aft it will go. At about 1.5 of the speed length ratio, the craft is entering the full planning mode, if the speed continues to go up the boat settles into a "bed" of sorts. This is because the bow wave trough coincides with the stern wave, the water is being squished out to the sides and reunites aft of the transom, where it can pile up quite high. At this point the hull bottom meets the surface of the water at an angle of incidence, generating dynamic lift.

All craft in displacement mode (all boats can be any operated in the three modes; displacement, semi or planning mode) lack the power to plane. If additional power is provided, they can be forced to plane, though some hull forms (shapes) are not well suited to planning.

[mackid068]

I like displacement boats. Think about the stability!!!!! Mmmm....biiiiiig keeeeeell....(big keel.).