Portland Navigation Plotter
- Movable disc enables magnetic variation to be set on the instrument
- Movable arm is divided into millimetres
- Captain Fields' protractor markings
- Comfortably covers the largest Admiralty Chart
- Pencil guide holes give precision loction
- Unique design ensures a truly parallel action
- Special "slip and grip" for ease of use
- Manufactured from clear acrylic
- 400mm in length