NAVIGATION
Distance at Sea — calculations
THE CURVATURE OF THE EARTH
Distance to Horizon (miles)
= 1.22459 x √Height above Sea Level (feet)
On the Beach (at 5.5 feet high)
On the Beach (at 5.5 feet high)
= 1.22459 x √5.5
= 2.872 miles
= 2.496 nautical miles
= 4.622 km
= 5055 yards
On the Quarter Deck (at 25 feet high)
On the Quarter Deck (at 25 feet high)
= 1.22459 x √25.0
= 6.123 miles
= 5.321 nautical miles
= 9.854 km
= 10776 yards
In the Masthead (at 120 feet high)
In the Masthead (at 120 feet high)
= 1.22459 x √120.0
= 13.415 miles
= 11.657 nautical miles
= 21.589 km
= 23610 yards
In the Nest (at 190 feet high)
In the Nest (at 190 feet high)
= 1.22459 x √190.0
= 16.880 miles
= 14.668 nautical miles
= 27.165 km
= 29708 yards
In the Lighthouse (at 513 feet high)
In the Lighthouse (at 513 feet high)
= 1.22459 x √513.0
= 27.736 miles
= 24.102 nautical miles
= 44.637 km
= 48815 yards
Notes
-
√ = square root
-
Height above sea level at eye level
-
Rounded to three decimal points
DID YOU KNOW...?
One nautical mile is equal to one minute of latitude.
SHIPS OF WAR — MURKY WATERS (Book One)
1791 — England's cannon remain ever silent as her shipping is ruthlessly preyed upon, a detestable state of affairs, though soon to be remedied...
England is ill prepared, Europe is in turmoil and the French Revolution is readying to sweep across the continent. A tedious uneasy peace poises on a knife's edge. Brittana rules the...
About "Ships of War" — a Naval Adventure Fiction Series
Aspects of navigation are an integral part of any ship in the age of sail. The hardships of such often mentioned the naval adventure fiction series "Ships of War" by Bradley John. From time to time, you too will be confronted (perhaps even confounded) by the nautical calculations suddenly presented, often in need to save the ship and their lives. Naturally, they were not afforded the ease of modern technologies such as GPS, computers or even rudimentary calculators.
The first instalment of the series is set in England in 1791, titled "Ships of War — Murky Waters". The reigning monarch of England is George III. Louis XVI is the monarch of France, but he is not exactly reigning, his authority somewhat diminished within the rising revolution. War is nigh and eventually is declared by France on 1 February 1793 (following the execution of Louis XVI on 21 January 1793).
Bradley John's series commences in 1791 in the prelude to war. It seems a solution must be found by the English Admiralty to resolve the piracy preying upon their merchant shipping. In doing so, they select a complete unknown, someone wholly dispensable, in particular, an unknown officer who had served under one Captain Horatio Nelson.