Captain Fields Standard 400mm Parallel Rules with Aluminium Links for Boat Use RWB434

Captain Fields Standard 400mm Parallel Rules with Aluminium Links for Boat Use

These standard Captain Fields pattern parallel rules are a British-made chartwork tool with a 400mm, nominal 16-inch length. The rules are precision injection-moulded in 5mm acrylic and joined by anodised aluminium link arms. Protractor divisions and compass-point markings are provided, while all four edges are bevelled to make the instrument easier to use on a chart. The linked-rule arrangement allows one edge to be moved while the other is held in place, helping you transfer a direction across the working area. This standard version is identified by its anodised aluminium links, an important detail when comparing the two catalogue variants.

Choosing and using this product

Choose a rule length that suits your chart table and the area over which you need to transfer a line. The 400mm length offers a substantial working edge, but it still needs enough clear chart space for the linked arms to move. Position an edge along the bearing or line you wish to transfer, hold that rule steady and move the other edge without changing the direction. Continue the movement as required, checking alignment against the chart’s compass rose or appropriate reference. Work on a stable, flat surface and take care not to let either edge slip while transferring a bearing. The protractor and compass-point markings provide reference information, but they do not remove the need to check chart alignment and the calculations used in navigation. Inspect the acrylic edges, markings and link movement as part of routine care, and store the rules so the working edges are protected. The standard and deluxe variants have the same catalogue length and acrylic thickness; the stated difference is the link-arm material. Select by the actual construction and size rather than assuming a different scale or accuracy rating for the deluxe name.

Product details

• Supplier reference: RWB434; Captain Fields pattern standard parallel rules.
• Length: 400mm, listed as 16 inches.
• Precision injection-moulded 5mm acrylic construction.
• Link arms: anodised aluminium.
• Protractor divisions and compass-point markings.
• Bevelled on all four edges; British made.