The fact is the marina is already there - just look at the video:
Sure looks like a marina with floating boat slips...
Many of the boats already there are of good size (25 ft+ long) and are sitting on floating boat lifts that need more than 5 feet of water. There's at least one sailboat there that has a ~6ft draft with its keel. So if the marina only had 5 feet of water, the skipper wouldn't be able to maneuver.
Sorry - your position isn't supported by the facts.