5% off

Weems & Plath 18" Parallel Rule

Size:	457 × 66 × 13 mm

£26.59 £27.95

Includes 20% VAT. Shipping calculated at checkout.

Delivery Information

We dispatch most orders within one working day.

Admiralty charts are printed to order and are dispatched within two working days. If you'd like to know our current dispatch time or if you're up against a deadline please get in touch and we will do our best to help.

Shipping is free on orders over £50.

We ship to the UK. If you're ordering from outside the UK, get in touch and we'll see what we can do.

Friendly Advice

Got a question or need help finding something? We're a seafarer-run business and we're happy to help.

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We're available seven days a week.

Returns

Not what you were looking for? No problem. We accept returns of items in as-sold condition within 30 days. Just let us know and we'll sort everything out, including the cost of return shipping.

Please note that Admiralty charts are not returnable as they are printed to order. See our returns policy for more information.

If anything arrives faulty or damaged, get in touch and we'll sort it out.

For Full-Size Charts

18-inch acrylic parallel rule with aluminium arms

A 18-inch (45.7 cm) parallel rule for plotting courses and transferring bearings on the chart.

Milled acrylic with bevelled edges, brushed aluminium arms, polished aluminium handles and non-slip cork feet, with a protractor scale (Captain Field pattern) along the edge for taking a bearing from any meridian when there is no compass rose nearby. It comes in a protective plastic sleeve, with a limited lifetime warranty.

How to use a parallel rule

Lay one edge along the course or bearing, hold it down, and move the other edge across the chart; then hold that edge and bring up the first. Walked like this, the rule carries the line to a compass rose or a position without losing its direction.

About Weems & Plath

Founded in 1928 by Lieutenant Commander Philip Van Horn Weems, Weems & Plath has a long history of making instruments for navigators, from the Weems Plotter to the Second Setting Watch.