Great place to visit on a sunny day as you can look over the harbour and there is a great selection of bars & restaurants (tends to be the chains).
Brighton
Updates
I'm sorry but the marina is a concrete wasteland dominated by an enormous ASDA, outlet stores, endless car parking and a McDonalds. If this sounds like you and you just can't wait to check out the plastic palm trees and tacky walk of fame then by all means visit! The only good thing about the marina is that you can walk from there to Rottingdean via the fabulous under cliff walk.
Is this your business?