It's early morning on May 14, 1741, on board the British warship HMS wager off the coast of southern Chile.

Below deck, 17-year-old midshipman John Byron waves through waste-deep water,

feeling his way along a dark passage. After nine months at sea, Byron knows every inch of this ship,

but right now it's utterly unfamiliar. The wager has run aground in a storm. Pinned between two rocks, it's being ripped apart by the waves.

The lower decks are already underwater, and it won't be long before this level is totally submerged as well.

Most of the surviving crew have already abandoned ship and reached safety on a nearby island.

Now, midshipman Byron is heading for the surgeon's cap.

He's got to convince the captain, who's bedbound with a broken shoulder, to join the rest

of the crew before it's too late. The wager shudders and lurches beneath him.

A candle floats by, and Byron grabs it and stuffs it into his pocket.

They've taken as many provisions off the ship as possible,

but they've had to leave most behind, and even a half-burned candle may come in handy.

Pulling himself around a corner, Byron kicks through the water to the surgeon's door and hauls it open.

The room is still dry, and Captain David Cheap lies on a cot inside, his arm wrapped in a sling, and his face pale.

He asks whether the crew is off the ship, and Byron says they've taken everyone they can.

For a moment, it seems that Cheap is determined to go down with his ship, but Byron won't let him.

The survivors will need their captain if they are to survive what comes next.

Reluctantly, Captain Cheap agrees.

Byron grabs the captain's great coat, which is hanging by the door.

Then he finds a cane in the corner of the room.

Gently, beazes the captain up out of the bed, and with Byron's help, Cheat gets to his feet.

The wager is lost, but the men

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