Divided with protractor markings (double reading) and compass points, these rules are made from 6mm acrylic, bevelled on all four edges with solid brass links. All other metallic parts are made from non-corrosive materials. Rubber pads are fitted to the underside to prevent slipping.

This is the budget version of the Captain Fields’ Pattern Parallel Rule for use in the classroom. It has rigid aluminium links. Available in 400mm size.

The Portland Course Plotter is an advance on all current designs. A bright green directional arrow prevents accidental reciprocal bearings and the edges are graduated for tide and boat speed. The base has a fixed grid so it is easy to plot latitude and longitude from your GPS system. Comprehensive instructions included.

Portland Single Hand Chart Dividers are made to a traditional design in brass finish with stainless steel points.

Made from strong acrylic, these triangles have protractor markings and compass points with reciprocals in red and a scale in millimetres. They are often used in pairs as a parallel rule.