Answer: Quite easily, I lay down, shut my eyes…..no sorry..sorry….. That’s my warped humour kicking in.. After rowing for most of the day I assume I’ll be ready for a bit of shut eye – on board I will have a bit of electronic wizardry called “CARD” Collision Avoidance Radar Detector that goes in to alarm should a ship/tanker approach. It has a range of up to 30 miles but there are variables such as wave height.