This has got to be the weirdest oceangoing vessel I've ever seen: The FLIP (Floating Instrument Platform) was a ship apparently built in 1962 as a research platform. After being towed to its target site in a horizontal, normal ship position, ballast tanks begin taking on water--and the ship pivots 90 degrees, sending the bow some 300 feet below the surface, while the tail end rides above the waves, bristling with cranes presumably used to lower equipment.
Why the pivot? In rough seas that would toss normal ships about, the FLIP's unique alignment allows it to "anchor" itself in the calm waters below the surface, making for an exceptionally stable (and portable) platform.