A diver is working at 12 msw for 90 minutes when he complains that he has a severe headache over his forehead. From which of the following is he likely to be suffering:

While your diver is in shallow water working there is a muffled thud and you realise there has been some sort of explosion nearby. When you recover the diver he is conscious but bleeding from the ears and nose. He is obviously injured. Which of the following is the best thing to do while you wait for an ambulance to arrive.

You get a diver who has not worked for you before. He does the first dive of the day at 09:00 and works well. After lunch one of the team points out to you that he is sitting in the corner of the van and has stopped talking to anyone. You go to see him and find he is a bit “odd” but he seems normal physically. What is the first thing you should suspect?