USS
Ranger, CV-4 and the first US carrier designed to be one from the keel up, IE not a conversion like
Langley,
Lexington and
Saratoga. She was small and slow (by WW2 carrier standards) but in the Atlantic she proved that having any carrier beats having no carrier.
Speaking of
Surcouf, has anyone seen the British WW1-era M-class submarines?
Navies did lots of screwy things with bridges, masts and observation posts (rangefinder/gun director points). Some of the British Grand Fleet ships had the foremast (with the observation post) behind the first funnel. And yes, the crews were blinded, asphyxiated and cooked by exhaust gases. So they moved the masts - and then one class later put them back in the same place. Masts are heavier than they look, and because of their height and weight you can't always put them where you want. But the 'champion' of bridge-construction-gone--mad would have to be the Japanese
Fuso class.
For me, the most interesting is the US Navy's love-affair with lattice (basket or cage) masts. From 1904 to the early 1940s all US capital ships were built with or refitted to have masts made of spiral--wound metal. Supposedly these were lighter and stronger than a conventional mast, and more shock-absorbing, which is important when you mount the range-finders and gunnery observation posts on them.
They were never completely successful. One weakened mast bent over when USS
Michigan hit a bad storm (see here:
http://www.ibiblio.org/hyperwar/OnlineLibrary/photos/images/h46000/h46283.jpg). There were extenuating circumstances, but other ships began to show metal fatigue in their masts, partly from the corrosive effects of coal and oil smoke. When the US sent ships to join the Grand Fleet in WW1 they closely examined British tripod masts and the lattice mast was eventually discarded. Some US battleships still had 'cage' masts at Pearl Harbor. Can anyone name two?