Weather Gauge

Weather Gauge

This is a naval tactic which utilizes the direction of the wind in relation to the position of the fleets in order to create a manoeuvrability advantage.

This tactic is still used today in the sport yacht racing.

Daniel Scotland

Author: Patrick O'Neill

URL: https://ageofsail.wordpress.com/2008/12/31/weather-gage/

British English

A very common term found in books about the age of sail is “weather gage”. It was an advantageous position to a vessel upwind of another. The logic is that the upwind ship gained manoeuvrability and the ability to move or rotate towards the downward ship freely. The admiral holding the weather gage held the tactical initiative, able to initiate battle by engaging on his opponent or to disengage by remaining upwind.

The fleet with the leeward gage could avoid battle by withdrawing to leeward, but could not force action. The fleet, or ship, to leeward could decline the fight by running away. An advantage exist in being able to hold your relative easting/northing while avoiding combat. The idea that the leeward fleet could not force action is only true if the meeting occurred far from land. In the Bay of Biscay, the Baltic, the English Channel, the North Sea, and the Mediterranean this was not the case.

Retreating downwind could be difficult once opposing fleets were at close quarters due to the risk of ships being raked as they rotate manoeuvre downwind. In addition, ships approaching from windward also ran the risk of being raked.

A second disadvantage of the leeward gage was that in instances of more than a light wind, a battleship that is sailing close hauled will be inundated by leeward under the pressure of the wind on its sails. The ships of a fleet on the leeward gage heel away from their opponents, exposing part of their bottoms to shot.

The ship on the weather gage is heeling at roughly the same angle as the ship to leeward, assuming they are similarly matched. While there may be some exposure of the hull below the waterline this is offset by the fact that on windward ship the lower row of gun ports would have to remain closed to avoid swamping the ship. This takes the largest calibre guns out of action. The guns which were safely above the level of the sea would then be limited to hitting what they could with the 5-degree elevation possible on the standard gun carriage. The leeward ship could fire all guns and quoins, inserted under the breech of the cannon, could depress the gun to compensate for the heel of the ship. It is worth noting that, ships were always vulnerable to holing below the waterline as seawater did little to slow the impact of a cannonball.

Smoke from the gunfire of the ships to windward would blow down on the fleet on the leeward gage. This could be considered a double-edge sword. In most instances the ships would be too close to each other for the smoke to make a difference (approximately twenty yards). However, in longer range combat, the smoke would reduce visibility for both parties and not be advantageous to anyone. It may be useful if one party decides to retreat after firing so that the smoke would increase their chances of a successful escape.