Manoeuvring a yacht under engine at close quarters in a marina close to other (expensive!) boats can be a daunting prospect for the inexperienced skipper - but it has to be done in order to take your boat off a pontoon to go sailing, and to berth her after a day on the water. Throw in fast flowing tides, and unpredictable wind which might blow from the bow or beam or stern, and the exercise becomes even more of a lottery - even for the experienced boat handler. Spiral bound.