Sailing into or leaving a strange harbour at night is never funny, but if you’ve no choice a little moonlight can make a big difference. If you can time your movements for a couple of hours or more after moonrise that’s a real bonus, especially if it’s over half-full. A decent almanac like Reed’s will dish up the information, but it’s a whole lot easier on a chart plotter. The little electric brain will work out the exact time for where you actually are. It even tells you whether it’s waxing, waning, full or nothing at all, and if you’re a proper sailor who’s interested in lowering the colours at sunset, it’ll put you straight about that as well.