Complex sentence: Generally the crew have lost control of the ship or abandonned the ship due to it sinking, being stranded on rocks or a shallow sea bed or simply because its means of propulsion has failed and it is drifting with the wind and tide.
Split into simpler sentences: Generally the crew have lost control of the ship or abandonned the ship. This could be due to it sinking, being stranded on rocks or aground on a shallow sea bed or it could simply because its means of propulsion has failed and it is drifting with the wind and tide.