To a landsman, like myself, a lot of the maneuvering described by authors who understand sailing and sailing ships approaches impenetrable. One of the most common terms we encounter is the “weather gage” and the desirability of achieving it.
There is no doubt that the Royal Navy placed a heavy premium on this position, but did it really do what many think it does?
Having the weather gage, put simply, means that the ship having the weather gage is upwind from its adversary. It was perceived to be an advantageous position prior to engagement by the Royal Navy but was thought to be a disadvantageous position by the French. Wikipedia gives the conventional wisdom on the subject but I think a lot of it is simply wrong.
The admiral holding the weather gage held the tactical initiative, able to accept battle by bearing down on his opponent or to refuse it, by remaining upwind. The fleet with the lee gage could avoid battle by withdrawing to leeward, but could not force action.
This is true, but the operative words here are “accept battle.” The fleet, or ship, to leeward could decline the fight by running away. There is a positive advantage to being able to hold your relative easting/northing while avoiding combat. The notion 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.
Even retreating downwind could be difficult once two fleets were at close quarters because the ships risked being raked as they turned downwind.
And ships approaching from windward also ran the risk of being raked.
A second disadvantage of the leeward gage was that in anything more than a light wind, a sailing ship that is sailing close hauled (or beating) will heel to 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.
This statement approaches hokum. 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 gunports would have to remain closed to avoid swamping the ship. This takes the largest caliber 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.
One also has to note that ships were always vulnerable to holing below the waterline as seawater did little to slow the impact of a cannonball.
Finally, smoke from the gunfire of the ships to windward would blow down on the fleet on the leeward gage.
One is more than a little unsure how this is an advantage to anyone. If two fleets were engaged at “pistol shot” the downwind direction of the smoke is irrelevant as the target is only 20 yards or so away. At longer ranges the smoke from the guns of both combatants served to make gunlaying more difficult for both sides by reducing visibility.
Dr. Douglas Allen of Simon Fraser University has done some work in examining the economic incentives that made the Royal Navy dominant from the late 18th Century through the end of the Age of Sail and concludes that the weather gage, in combination with the requirement to fight in line of battle, had the effect of encouraging admirals and captains to fight. If fleets were engaged it was nearly impossible for a reluctant captain to avoid combat by skulking off downwind.
This, in my view, makes more sense that the perceived tactical advantages of the position.