If you’re covering significant distances that people live in, you can expect to spend a decade or sometimes more in court before being able to build - if ever.
Because of course there are the environmental reviews, the impact assessments, etc. and each of those will be hundreds to thousands of pages long, and you’ll likely have to fight over each page, also in court, with folks who don’t like that you’re going to dig up that random patch of flowers to install your power line or whatever.
And that is assuming you’re lucky enough to not have any endangered species in the way, in which case you might literally not be able to build at all if it is in an area you have no choice to go through.
So far no one is staking out patches of ocean floor, and generally even if they did, the topography is usually more forgiving there. So all you need is landing approval, which means one government and one compliant landowner on each side somewhere along each coast that is close enough to an existing grid that you can interconnect to it. Much more solvable. Still not easy or straightforward.
In California it took me 4 years and $18k worth of professional help to get approval to do completely standard fuel reduction work on a completely uninteresting plot of land that was super overgrown with brush and dead trees - with no one objecting to it - in the middle of a historic wildfire crisis in California that actually expedited the process.
I had to notify 10 something local native tribes (in case they maybe were somehow attached to the land, which they weren’t), had to do a detailed archeological survey, had to have a licensed biologist do a detailed walkthrough to look for endangered species (there were none).
Meanwhile the 3 largest fires in the states recorded history burned nearby, and they wouldn’t let me clear brush and remove dead trees from a clear fire hazard area and it’s a miracle the place didn’t burn to the ground.