people struggle to learn Secondary Ports - it is one of the main problem
areas on RYA courses. This simple graphic method shows how simple
Secondary Port Calculations can be.
This A4 encapsulated sheet will make life so much easier.
one explains how the information that you need is laid out and what
that information means. It then shows a worked example of Time
Differences and side two has a worked example of Height Differences.
Side two also has plenty of space for your own calculations.
Matt encapsulation means that a 2B pencil may be used directly on the plastic.