In maritime law and tradition, there exists a duty to render assistance to those in distress at sea. The International Convention for the Safety of Life at Sea, known as SOLAS, obliges the master of every ship who receives information that people are in distress to proceed to assist them at full speed. The duty is clear in the legal text. The practical enforcement, in the middle of an ocean far from any regulatory observation, is less clear.
Alvarenga described approximately twenty container ships that crossed his path during the drift without stopping. This claim has been treated with skepticism by some commentators and accepted as likely accurate by others who understand the conditions of maritime travel in that part of the Pacific. The truth is that both responses have some basis.
The skeptical response notes that it is difficult to verify a claim that depends entirely on the account of the person making it, and that the psychological conditions of extreme isolation might distort memory and perception. The accepting response notes that the track from the Mexican Pacific coast toward the Marshall Islands passes through shipping lanes used by large commercial vessels traveling between Asia and the Americas, and that spotting a small, motionless 25-foot boat from the bridge of a container ship traveling at 20 knots is genuinely difficult under normal conditions.
Consider the geometry: a container ship’s bridge sits perhaps 30 to 40 meters above the waterline. The horizon from that height is approximately 20 to 25 kilometers away. A 25-foot fiberglass skiff sits very low in the water — its freeboard, the height above the waterline, might be two or three feet. At any significant range, such a boat is essentially invisible against the background of ocean chop. If it has no radio transmitter and no radar reflector, it produces no electronic signature that a ship’s instruments would detect. The ship’s crew might be watching ahead for navigational hazards — other vessels, floating debris, land features — but a small open boat far from any charted traffic would not be where their attention is focused.