The pier is usually held in place by vertical poles referred to as pilings, which are embedded in the seafloor or by anchored cables.
[1] Frequently used in marinas, this type of pier maintains a fixed vertical relationship to watercraft secured to it, independent of tidal, river or lake elevation.
[8]andShaped like a U, the pontoon resembles a miniature floating dock, and consists of two parallel decks joined by a submerged framework.
When the flying-boat has landed, it is warped into position by the ground crew, and is drawn tail-first into the pontoon, coming to rest with the hull between the two sections of decking and above the submerged frame.
[2]A Braby pontoon constructed at Evans Bay in Wellington, New Zealand in 1951 consisted of 124 large square steel tanks connected together and ballasted with water and oil.