When a load of ships need to be shipped or when an oil rig has been built but needs to travel to its permanent location, the Blue Marlin gets called. The enormous ship can carry 75,000 tons.

Thus, we see in the picture below that it can hold more than 20 regular sized barges….

And here we see it hauling the largest offshore structure in the world, BP’s Thunder Horse oil rig, which the Blue Marlin carried 16,000 miles from Korea to the Gulf of Mexico…

Sometimes, the ship gets a little break and only carries “small” oil rigs…

…or submarines…

…or a destroyer…

…or a couple of minesweepers…

…or a seafaring radar system.

Nothing this ship is hired to transport is small enough to be loaded with any crane, so the Blue Marlin’s deck is designed to be submersible. When its ballast tanks are filled with water, the weight sinks the deck 43 feet under the surface. The freight is then floated over the deck and the ballast tanks are emptied, causing them to resurface and lift the load out of the water.

In the photo below, the deck is submerged as the Blue Marlin offloads an oil rig…

This is all, obviously, highly-specialized and astronomically expensive work, but that doesn’t mean that there is any shortage of jobs for the Blue Marlin. There is so much demand, in fact, that the company that owns Blue Marlin is currently building an even bigger transport ship that will carry up to 110,000 tons.

(via The Daily Mail, Wikipedia)