There was a 'cable area' marked on the chart in the Abacos and we decided to just stay clear. A trawler pulled up and dropped the hook right on the area marked cable on the chart. The water was warm and only 10 feet deep so we decided to jump in and take a look. His anchor was hooked under the cable and after we told him about it we offered to dive down and pull the damn thing off which we did.
It was 3 cables wide over about a 30 foot span so I figure it was an important electrical connection to the island. Who knows, if he had just raised the hook it could even have been a ZAP destroying his vessel and shorting out the island. Don't know but there must have been a lot of power flowing through those cables.
I say stay away or at least dive down and take a look if the water is warm and clear.