Chart Drawing Triangle Ruler for Ship Drawing 300mm Large-Scale Triangle Ruler for Distance Measurement Teaching Engineering Design

Determine longitude on protractor to determine course or bearing
The protractor's allows placing a dividing point or pencil on a point of the hole
A string can be used to fix the stopwatch used on the hole for a long distance of course.
When charting, it is used to draw the bearing line or heading line, and measure the bearing line or heading degree.
colour:Transparent
Material:plastic
size:300mm
Package Contents:
2*Nautical chart drawing triangle ruler
Only the above package content, other products are not included.
Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.