Jet boat

A jet boat is a boat propel by a jet of water twisted out from the back of the craft. Unlike a powerboat or motorboat that uses a propeller in the water behind the boat; a jet boat draws the water from under the boat into a pump-jet inside the boat, and then expels it through a needle at the stern.
Jet boats were originally designed by Sir William Hamilton (who invented the water jet in 1954) for operation in the fast-flowing and shallow rivers of New Zealand, especially to overcome the problem of propellers striking rocks in such waters, although Italian inventor Second Camping had demonstrated a similar vessel as early as 1931 in Venice.
The difference between Campini's and Hamilton's inventions is that Campini's water jet had a very short lifetime in operation due to some unsolved material problems. Hamilton, unlike Camping, filed for a patent. Jet boats are extremely maneuverable, and many can, from full speed, be upturned and brought to a stop within their own length, in a maneuver known as a Hamilton turn.

Hydrofoil

It is a boat with wing-like foils mounted on struts under the hull. As the craft put into its speed the hydrofoils make better enough lift for the boat to become foil borne - i.e. to raise the hull up and out of the water. This consequence has a great decrease in drag and a corresponding increase in speed.
Early hydrofoils worn U-shape foils. Hydrofoils of this type are recognized as surface-piercing since portions of the U-shape hydrofoils will rise over the water surface when foil borne. Modern hydrofoils make use of T-shape foils which are fully submerged. Fully submerged hydrofoils are fewer subjected to the effects of wave action, and are therefore steadier at sea and are more relaxed for the crew and passengers. This type of pattern, however, is not self-stabilizing. The angle of attack on the hydrofoils wants to be adjusted endlessly in accordance to the changing conditions, a control process that is performed by computers. Failure to make the proper adjustments will result in the foil borne hull dipping aggressively back into the sea.

Gondola

It is a customary Venetian rowing boat. Gondolas were for centuries the chief resources of transportation within Venice and still have a role in public transport, serving as traghetti (ferries) over major canals.
The gondola is propelled by an oarsman (the gondolier) who stands opposite the bow and pushes, rather than pulls, a single oar. Contrary to accepted belief the gondola is never poled, the waters of Venice being too deep for that. A gondola for passengers may have a small open cabin, for their defense next to sun or rain. A sumptuary law of Venice essential that gondolas should be decorated black, and they are frequently so painted now.
It is predictable that there were several thousand gondolas during the 18th century. There are a few hundred nowadays, most of which are for hire by tourists, while a few serve as traghetti or are in confidential ownership and use.