She supported Allied operations in the Indian Ocean and South West Pacific Areas until she became a training ship at the end of 1944.

Saratoga returned to combat to protect American forces during the Battle of Iwo Jima in early 1945, but was badly damaged by kamikazes.

The Lexington-class ships were originally designed to be battlecruisers, with heavy guns, high speed, and moderate armor protection.

On the minus side, a converted battlecruiser would be 0.5 knots (0.93 km/h; 0.58 mph) slower than a specifically designed carrier, have 16 percent less hangar space, less emergency fuel and, with "narrower lines" aft, not as wide a runway for which to aim.

[3][N 2] The bottom line, with the signing of the treaty, was that any capital ships under construction by the five signatories (the United States, Great Britain, France, Italy and Japan) had to be canceled and scrapped.

[3] The clause (Chapter II, Part III, Section I, (d)) read: No retained capital ships or aircraft carriers shall be reconstructed except for the purpose of providing means of defense against air and submarine attack, and subject to the following rules: The Contracting Powers may, for that purpose, equip existing tonnage with bulge or blister or anti-air attack deck protection, providing the increase of displacement thus effected does not exceed 3,000 tons (3,048 metric tons) displacement for each ship.

A disadvantage was the formation of a thick layer of water, part of the bow wave, which would creep up along the forward side of the hull at higher speeds, although this could be reduced to some degree by careful design of this area.

A 20-by-26-foot (6.1 by 7.9 m) section of the flight deck adjoining the rear edge of the elevator could split down the centerline to lift aircraft otherwise too long.

[8] In early December 1941, Lexington was ferrying 18 U.S. Marine Corps Vought SB2U Vindicator dive bombers to Midway Atoll and at that time she embarked 65 of her own aircraft, including 17 Brewster F2A Buffalo fighters.

[14] Before the Battle of the Eastern Solomons in mid-1942, Saratoga's air group consisted of 90 aircraft, comprising 37 Wildcats, 37 Dauntlesses and 16 Grumman TBF Avenger torpedo bombers.

[16] Turbo-electric propulsion had been chosen for the battlecruisers because American companies struggled to produce the very large geared turbines necessary for such big ships and was retained when they were converted into aircraft carriers.

[11] One advantage of turbo-electric drive was that the substitution of flexible electric cables for bulky steam-lines allowed the motors to be mounted farther aft; this reduced vibration and weight by shortening the propeller shafts.

[18] Four General Electric turbo generators powered each propeller shaft and each was rated at 35,200 kilowatts (47,200 hp), 5000 volts and 4620 amps of direct current (DC).

Sixteen water-tube boilers, each in their own individual compartment, provided steam for the generators at a working pressure of 295 psi (2,034 kPa; 21 kgf/cm2) and a temperature of 460 °F (238 °C).

They demonstrated a range of 9,910 nautical miles (18,350 km; 11,400 mi) at a speed of 10.7 knots (19.8 km/h; 12.3 mph) with 4,540 long tons (4,610 t) of oil.

[22] The Lexington class' anti-aircraft (AA) armament consisted of a dozen 5"/25 caliber guns, six on each side of the ship on single mounts.

They had a rate of fire of 550–700 rounds per minute and were exceedingly reliable,[24] however, their projectiles were too light and too short ranged so they were replaced by license-built Oerlikon 20 mm autocannon beginning in 1942.

The third deck over the ships' machinery and magazine was armored with two layers of special treatment steel (STS) totaling 2 inches (51 mm) in thickness.

The torpedo defense system of the Lexington-class ships consisted of three to six medium steel protective bulkheads that ranged from .375 to .75 inches (10 to 19 mm) in thickness.

[36] Lexington and Saratoga were used to develop and refine carrier tactics in a series of annual exercises before World War II.

[41] Lexington's turbo-electric propulsion system allowed her to supplement the electrical supply of Tacoma, Washington, in a drought from late 1929 to early 1930.

[42] Both ships were assigned to the Pacific Fleet and were based at Pearl Harbor in December 1941, although, at the time of the Japanese attack, neither of them were in port.

[43] Saratoga had completed a major refit at Bremerton, and, following work up, had arrived in San Diego to embark her air group.

A planned attack on Wake Island in January 1942 had to be cancelled when a submarine sank the oiler required to supply the fuel for the return trip.

[45] Lexington was briefly refitted in Pearl Harbor at the end of the month and rendezvoused with Yorktown in the Coral Sea in early May.

Vapors from leaking aviation gasoline tanks sparked a series of explosions and fires that could not be controlled, and the carrier had to be scuttled by an American destroyer on the evening of 8 May to prevent her capture.

After lengthy repairs, the ship supported forces participating in the Guadalcanal Campaign and her aircraft sank the light carrier Ryūjō in the Battle of the Eastern Solomons in August 1942.

[47] In 1943, Saratoga supported Allied forces involved in the New Georgia Campaign and invasion of Bougainville in the northern Solomon Islands and her aircraft twice attacked the Japanese base at Rabaul in November.

[49] While under repair, the ship, now increasingly obsolete, was permanently modified as a training carrier with some of her hangar deck converted into classrooms.

[50] Saratoga remained in this role for the rest of the war and was used to ferry troops back to the United States after the Japanese surrender in August.