For millennia, ships have been used to fish; transport passengers and cargo; and bring divers to particular locations to harvest sea life, salvage wrecks, or conduct studies. Anchors must be raised or lowered; rigging adjusted; and cargo loaded, stowed, and ultimately delivered. Employing navigation, equipment, and methods, ships must be steered to their destination despite the vagaries of wind and wave, communicate with other ships or those onshore, and operate within parameters that may encompass issues such as efficiency and safety.