Wind and swell are the main drivers; the tidal range and phase amplify them. Answer five quick questions and get a 1-5 risk level with a clear go, caution or postpone call.
Pick today's conditions and press Assess risk to get your coastal risk level.
Base = 0.55×wind + 0.45×swell + rain. This makes wind and swell the dominant factors — they decide how rough the sea and rock surfaces get. The tidal-range multiplier (0.9 / 1.0 / 1.15) then scales the result, because spring tides run higher and faster. The flood-phase adder (0.7 on a rising tide, 0.5 near high) pushes exposed low-ground routes up one notch. The total is clamped to 1-5.
1-2: gentle, routine coastal conditions. 3: caution — exposed routes need extra planning. 4: postpone low-ground and water activities; watch the forecast. 5: do not go to the coast; strong wind + large swell is how rock-route rescues happen.