Vikings. Beyond the Legend.

The Íslendinga saga tells a marvellous tale, of a boat that was shipwrecked on a crossing from Norway to Iceland in the thirteenth century.  Four men managed to survive thirteen days by feeding off the walrus-hide tackle with butter, the only part of the ship that was salvaged.  Put us in the picture.
Image:  http://seajunk.com/cargo/pirate-ship-block-and-tackle-rigging/