I couldn't find the ref i wanted, only in Wiki which I take with a grain of salt.
I did find this though re U2 carrier ops (plus other information)
"
It was also decided to see if the U-2 could operate from an aircraft carrier. A U-2 was equipped with a strengthened tail and an arrestor hook. A set of wing spoilers was also added to ensure the aircraft could actually land accurately on the flight deck, rather than floating over the arrestor cables and the carrier capable aircraft were re-designated U-2Gs. One aircraft, Article 349, was AAR and carrier capable and was the only U-2H."
Lockheed U-2S
A couple of good photos here
Aerospaceweb.org | Ask Us - U-2 Aircraft Carrier Operations