A vessel towing a large barge is the least likely to be able to rescue someone, especially in the likely sea conditions with a strong wind. He had little reason to be certain of his fuel situation. Deciding to turn a few minutes earlier would have got him to land.
The following extracts surprised me:
"During the flight, the pilot was in contact with his mother sending numerous text messages. Around 1525 the pilot sent a text stating that there was a severe headwind and expressed his concerned about having enough fuel to complete the flight."......." The pilot sent a picture to his mother about1637 which showed a marine vessel towing a barge in the water below his location. The pilot broadcast a mayday call over the Port Angeles UNICOM frequency at 1638:47."