被水托起來，貼著水面跑
這一支就是核心畫面本身：速度夠快時，水從下面把平底托住，東西就跑到水面上去，只剩一小塊碰水。
verb · B2
If a boat hydroplanes, it goes so fast that its front lifts and the bottom rides along the top of the water, touching only a little of it, instead of pushing through it.
貼水疾馳
核心畫面
Picture a flat board pushed across water faster and faster. At slow speed it sinks in and has to shove the water aside. Past a certain speed the water stops letting it in and starts holding it up, so the board rides along the top and barely touches anything. Almost everything this word means can be held in that one picture: the flat shape that water lifts, and the moment something climbs up onto the surface and rides there.
可以想成一塊平板被推著在水上跑。速度慢的時候，平板陷在水裡，一路把水推開，很費力。速度一過某個點，水就不再讓它陷進去…更多收起
可以想成一塊平板被推著在水上跑。速度慢的時候，平板陷在水裡，一路把水推開，很費力。速度一過某個點，水就不再讓它陷進去，反而從下面把它托住。平板於是貼著水面滑，幾乎不碰到什麼。這個字的多數用法，都可以放回這個畫面：一塊被水托起來的平面，以及某個東西「爬上水面開始滑」的那一刻。船是這樣變快的；車在雨天打滑，也是同一件事發生在不該發生的地方。From the word’s history
Wiktionary gives the word as hydro- plus plane, with hydro- going back to Ancient Greek hudor, water. English plane carries the idea of a flat surface and of sliding along one, and it is also the ordinary word for an aircraft. Both readings show up in this word's uses.
Wiktionary 記的組成是 hydro- 加 plane；hydro- 一路回溯到古希臘文 ὕδωρ（水）。英文的 plane 既有「平面、沿著表面滑」的意思，也是「飛機」的日常用字。這個字的各種用法，正好分別落在這兩層上面——這一點是本字用法的觀察，不是來源裡寫死的說法。
Wiktionary entry for hydroplane, kaikki extract (source_ref kaikki:3f6f69a190036ae4:1212810956): etymology tree PIE *wed- > Ancient Greek ῠ̔δρο- > English hydro-; 'From hydro- + plane.'
Three branches
水裡的翼：一片斜斜的面
核心畫面裡負責「把東西托起來」的，就是那塊平面。這一支把注意力從整艘船移到那塊面本身——水流過斜面，斜面就得到一股推力。
noun · C1
A hydrofoil: a fast boat with wing-shaped parts fixed underneath it. As the boat speeds up, those wings lift the body of the boat out of the water, so only the wings stay under the surface.
水翼船
能停在水上的飛機
這一支跟核心畫面的連結比較鬆：它用的是 plane 的另一層意思——飛機。共通的只有 hydro-，也就是「跟水有關」。
noun · B2
A plane that can take off from water and land on water. Instead of ordinary wheels it sits on floats, or its body is shaped like a boat.
水上飛機