Here's from a nautical dictionary [Origins of Sea Terms, John G. Rogers, Mystic Seaport, 4th printing]:

"Cable: The anchor line, now chain or rope (or both, depending on the size of the craft), earlier of course always rope, and cable-laid. The term came, via French, from the Latin word 'capalum' for halter.

Cable Laid: In rope days on big ships, heavy lines, such as shrouds and hawsers, were usually made of three three-strand ropes, the cable being of opposite lay, or twist, to the components..."

So, it sounds to me that in Fagles' translation what we would imagine would be the large ships under Odysseus' command each 'casting off' of anchor lines--or anchors a-weigh. Interesting. We've discussed anchors a-weigh before as a curiosity since the anchors weight moves from the ocean back onto the ship itself. In casting off cables, the anchor cables are actually coming back to the ship. Makes sense since Odysseus is often going to islands that are not ports of call, but deserted shores.