Yes, i do get claustrophobic (rarely, but yes). If the effort to go forward is hard, you need to take in account that there won&#x27;t be space to turn around and swim it head first back. So you need to keep in mind that you might need to &quot;finger walk&quot; yourself back - backwards! That is sometimes an adrenaline accelerator and keeps you from doing stupid stuff.<p>About nitrogen: probably one of the most impotent parts is gas planing: we transport and switch gases suitebale for the depth.. before every dive there is a lot of math.