We're in the big African Queen inflatable, cruising alongside an anchored trawler. It's more rust than metal - the ship is rotting away. The foredeck is covered in broken machinery. The fish deck is littered with frayed cables, and the mast lies horizontally, hanging over the starboard side. A large rusty Chinese character hangs on railings above the bridge, facing forward. It reads 'happiness'.

Zizi - our Chinese translator - shouts a greeting. A head pokes out from the accommodation, puzzled at this disturbance. A female voice, out here? He picks his way through the debris to the side of the ship. He's friendly, but a bit perplexed at our presence. Sarah asks questions - Zizi translates. He's the 2nd mate, and says that he's been sitting here on his own for five days, awaiting a new crew, He doesn't know when they'll arrive. The trawler itself has been anchored here, at this spot, for three months.

"Is this ship ready for fishing?" we ask. "Yes, of course", he looks around, gestures at the deck. He seems surprised that we would ask. We're amazed it's even floating.

Moff turns the boat, taking us to another of the rusting fishing vessels, 70 nautical miles (130km) off the coast of Guinea, West Africa. We had been told this was where old pirate fishing boats were left at anchor, abandoned. We didn't expect to find living people on board the dying ships.