First Ventures Flashcards
Pilotage
Scale - Degrees subdivided into 60 minutes equivalent to 60 nautical miles subdivided into 10 decimals called cables. Named after span of nelsonian warships anchor rope.
Mile at sea is 2000 yards so cable is 200 yards.
Depth - 9 small 6 is 9.6 metres. If underlined then may be dry at low tide. All depths are at Chart Datum which is water level at LAT Lowest Astronomical Tide. Add transducer depth to chart readings to get accurate depth and deduce draught of boat to know how shallow you can go before running aground.
High and Low water - Tide tables
Tidal data sorted by standard and secondary ports.
Make sure you are reading the time correctly BST or GMT (UTC).
Tide numbers given in meters and show depth which water will stand above chart datum.
