From time to time, we all imagine we’ve anchored closer to the shore than is actually the case. To assess how far off the beach you are, don’t rely purely on first impressions. Spot something whose magnitude is recognisable in everyday terms – a person walking a dog, perhaps; or a bus, a flagstaff or a cottage. Place this in the context of how it would look down your street, across a rugby field or a car park, and your judgement will be assisted by known experience. When you are concerned about your distance from a ship, check to see if the mate is on the bridge wing. He may fool you by being only four feet tall, but it’s unlikely.