Off the island of Guam, we find a floating dry-dock. I’d assumed the cargo was craned into the dry dock, but instead the dry dock slightly submerges itself (just like a submarine) so that the ship (or in this case, a real submarine) can drive into the u-shape of the dry dock. The dry dock then pumps out the water to raise itself and the cargo above the surface. Simple really.

Guam have three different floating dry-docks, this is the largest and is worth a staggering $24 million. The submarine is the USS San Francisco which stopped by here in January 2005 for emergency repairs after hitting uncharted underwater rocks.

Thanks: Martin Kaae

Edit: fixed the link.

Just off the coast of St. Croix, U.S. Virgin Islands, is what looks rather like a Rum Slick - waste from the production of molasses at the nearby Cruzan Rum Distillery.

Certainly the dark patch starts directly offshore from the point where the distance is shortest between the distillery and the sea - but surely it would be madness to so obviously pollute such beautiful waters, especially when the island’s economy relies so heavily on tourism?

Thanks to Joshua Germany.