(in diving) a dive in which a complete backwards somersault is performed before entering the water feet first.
 Example sentencesExamples
-  We'll have to do back flips and full gainers with a three quarter twist.
 -  Some older divers were practicing, and lo and behold they were doing full gainers, and half gainers and doing them very nicely.
 -  But going swimming and doing full gainers off diving boards helped out soo much.