The effects of gravity move at the speed of light (299,792,458 meters per second).
Gravity waves are not true waves but variations in the measured pull of gravity caused by a rapid movement of mass, such as rapidly orbiting large black holes that are relatively far apart.
If you had a sensitive gravimeter, it would give a wavelike reading.
No, gravity waves could not aid in reaching a faster than light velocity.
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there are two other things that go the exact speed of light other than light.gravity and time.its impossible to go faster than the speed of light its like being somewhere that isnt created yet thus impossible
No, that isn't true. Gravity waves exist, but they only travel at the speed of light, not faster (and one could not "piggyback" on one for FTL).
There are physically plausible scenarios for FTL travel being considered, mostly revolving around Alcubierre's work, although right now none are known to work.