I want to know, Where is the highest Bungee jump above sea?
The highest jump is at the Macau tower, at 233m, but it's technically a controlled descent, not a true bungee. That's the Skyjump. They do however, have a bungee with a guide rope there too. However, it's not over sea or water, as you requested.
So then you have to look at the jump from the top of the Verzasca Dam near Locarno, Switzerland. It appears in the opening scene of the James Bond film GoldenEye, and is 220m high!
The Bloukrans Bridge Bungy has been operated by Face Adrenalin commercially since 1997 and uses a pendulum bungee system. It is 216m high, from the platform to the river below. So if you're wanting one over water, that would qualify as the true highest, and indeed is the highest bridge jump in the world.
However, if you're wanting one over the sea as in ocean (so not river), then you're going to be looking at the 150m jump in Helsinki, Finland.
According to this list: http://travel.cnn.com/explorations/life/worlds-15-highest-bungee-jumping-sites-479316
and crossing it with the description here: http://www.skybreakers.com/eng/suomenkorkein_eng.htm
apparently the highest bungee jump above/over the sea is in Kaivopuisto, Helsinki, Finland. The jump is done from 150 mts high.
It's very likely that other jumps over the sea, from higher heights, have been done. This is the highest commercial one (commercial in the sense - schedule or arrive, pay, do!).