I still have a few more sentences I'm not sure of. Thank you very much.
1) He was very hungry but he had no time to waste. So he filled his pockets with dry biscuits and ate them as he wandered about.
2) He used spare yardarms and several spars of wood to construct a raft. When the raft was strong enough to load, he lowered all the provisions onto the raft.
3) He then made use of the rising tide to navigate back to the shore with his cache.
4) Robinson himself tells the story. It is a first-person narrative in diary form.The events are described in chronological order. Robinson acts in a very practical way and has no time for intellectual speculations.
5) Robinson gets upset when he realises that if all the crew had got on board the boat they would have probably been safe. He ends his reflection when he sees that it is useless to grieve over past mistakes.
1. comma needed
5. commas needed
Everything else is fine.