The Admiralty chart, simplified

A modern Admiralty chart is a small miracle of compressed information. Depths in metres, tidal stream tables, light characteristics, restricted areas, buoyage, conspicuous landmarks, magnetic variation, depth contours, foul ground, wrecks — the whole working environment of a coastal passage, on one folded sheet. It is also visually loud, which is exactly what you want at the chart table and exactly what you do not want on a mug. Redrawing one is mostly a question of what to leave out.

What we keep

Soundings. Always soundings — the numbered depths scattered across the open water are the chart’s most recognisable feature, and removing them empties the design. We keep them sparse rather than complete: enough to suggest the seabed, not so many that the page becomes a price list. The principal contour lines stay too, drawn at a single thin weight.

Place names. Three or four of them, in restrained type, in the places where the chart itself names them — never invented. Mounts Bay has Penzance, Marazion, Newlyn, and the Mount. Falmouth has St Anthony’s, Pendennis, Black Rock, and the harbour entrance. Anything more and the chart starts to read as a road atlas.

The compass rose. Charts have them; mugs benefit from them. We draw a simplified rose with the four cardinal points marked at full length and the intermediate ones implied. No degree gradations. No magnetic variation arrow.

What we drop

Tidal stream diamonds. Restricted areas. Cable runs and pipelines. Anchorage symbols. Light characteristics. Buoy names. Magnetic variation tables. Notes to mariners. The chart datum panel. Every one of these is essential at the chart table and pointless on a mug. They go.

The lines we redraw

The coastline gets the most attention. On the chart it is rendered with a fine, slightly mechanical line — we redraw it freehand, keeping the silhouette but loosening the texture. It reads better at mug-base scale and stops the design looking like a printed photocopy of someone else's work.

Five charts so far

Mount's Bay, Falmouth Approach, Padstow Bar, the Helford estuary, Carrick Roads, and Land's End to Scilly. Six, if we count the Scilly chart as separate from the passage chart. We add a new one every few months, working through the Cornish coast methodically rather than by request. The order is the order we got round to drawing them in — not a ranking.