Navigation and Seamanship (Inland and Coastal Waters)
Navigation and seamanship is where the exam checks whether you can plan and execute a passage on a classified waterway, keep the vessel in the fairway and prove that the water under and above you is sufficient.
Reading the waterway
- Waterways are graded into zones 1 to 4. Zone 1 covers waters of maritime character with tide, swell and coastal buoyage (IALA region A); zones 2–4 cover inland waterways of decreasing size. Your certificate states the zone you may operate in.
- Soundings refer to a reference level, not to today's water. On the Danube this is the RHM (reference water level) at the gauge; actual depth = charted depth + (current gauge level − RHM).
- Bridge and overhead cable clearances are also given at RHM, so a rising river eats your clearance centimetre for centimetre.
The fairway
Buoyage follows CEVNI: red marks define the right bank looking downstream, green the left. Sector lights, cardinal marks and danger marks supplement buoys at bends, groynes and bridge piers. Coastal passages use IALA-A lateral marks and tide tables.
Worked example
A bridge is marked with 6.20 m clearance at RHM. The gauge stands 0.90 m above RHM. Your air draught is 5.00 m and company policy requires a 0.30 m margin. Available clearance = 6.20 − 0.90 = 5.30 m. Required = 5.00 + 0.30 = 5.30 m. That is exactly zero spare margin, and a passing vessel's wash or a further 10 cm rise breaks it: wait for the level to fall or reduce air draught further.
Traps
Treating charted clearance or depth as fixed; ignoring squat in shallow water (it grows sharply with speed); cutting the inside of a bend where the fairway runs outside; anchoring in the fairway.