whaleback

[ hweyl-bak, weyl- ]

/ ˈʰweɪlˌbæk, ˈweɪl- /

Nautical.

something shaped like the back of a whale, as a rounded hill or an ocean wave.

Origin of whaleback

First recorded in 1885–90; whale¹ + back¹

I can't make out what they are on; but it looks like a whaleback to me, with her upper works carried away.

Across India |Oliver Optic
With ample artillery and fresh reserves at our command we were determined to gain the summit of the whaleback in a final drive.

The Story of the Great War, Volume VIII (of VIII) |various
An artistic illustration is given of the "whaleback" steamer, used principally on our Northern lakes.

My Native Land |James Cox
In the centre it rose to probably six feet and then fell very gradually, whaleback fashion, to the south.

Over Prairie Trails |Frederick Philip Grove

He went by the Suburban, because he wanted to go over to the avenues, and Cowles went down by the Whaleback.'

Against Odds |Lawrence L. Lynch

whaleback

/ (ˈweɪlˌbæk) /

something shaped like the back of a whale

a steamboat having a curved upper deck