By explanation : How can I pour concrete foundation inside sea or ocean ?

thanks for invitation -

Of easy things because their are some of special machines was designs for these types of used  as a first stage ( Pumps) .  phase after which the site preparation (drilling) to the process of casting the concrete like these works   ETC       !!!!

for this , need take away water and after put concrete . 

example : put pipe big diameter , take away water and after concrete.

.....also put basic foundation  ( ready made) in the point ...... e.t.c.

also there is other method