Semi-submersible ships are the only vessels capable of loading, transporting and off-loading extremely heavy equipment. These mighty ships are used to carry entire gas refineries, huge oil drilling rigs, and even warships and submarines, on lengthy journeys across the globe.
Hannu's Boatyard is a site by a Finnish guy who offers free plans for two dozen simple plywood boats you can build, along with photos illustrating the build process of each. He also describes basic woodbending technique and some of the design process, in a pleasing writing style that makes me want to get off the internet and make things. My favorites: Portuguese style dinghy; tiny stubby halfpea; round, Welsh-style coracle -- if you click on no other link today, click on the coracle link and scroll down at least to the black and white photo.
The National Maritime Museum, Greenwich has some excellent online collections related to maritime history and technology, including telescopes, marine chronometers, sundials, and a whole lot more. Some stuff I've been looking at: John Harrison's chronometers (described in Dava Sobel's book Longitude), polyhedral sundials, and pocket globes.
The Mother of All Maritime Links. Feeling a little landlocked? From "Pirates" (over twenty links) to "Weather & Tides," from plain old "History" to "Music" and beyond, this site is one of the more comprehensive available.