We do know that a lot of the design choices around the pier were environmentally focused.
I'm SURE there is a monetary savings achieved by lengthening a pier versus dredging the seabed to accommodate a cruise ship, but part of the agreement with the Bahamian government to obtain and develop this land was contingent upon satisfying an Environmental Impact Assessment and approval of an Environmental Impact Plan (both of which extend FAR beyond just the pier, and include the wildlife both in the sea and on the land).
The Heads of Agreement (HOA) contract with the Bahamian Government has been made public record and can be found hosted on DCL Blog
here
Of note, on the above linked page, you can see the initial site development proposed plans include this long pier in the place it is today, dating back to 2019 when the agreement was signed. Well before the EIA had been performed. They had been doing their own assessment for years prior and I'm sure had been in negotiations with the government during that time. They knew this pier was the environmentally sustainable solution.
In 2021, once the EIA had been completed, DCL held a public meeting, the transcript of which can be found online
here
And the meeting can be viewed on YouTube here:
Here is a quoted section from Dr, Mark Penning that touches on why they chose the pier they chose, and how they decided where to place it. (Emphasis mine):
And, while it is wholly unrelated to this discussion, I'm going to add in a quote about those ruins he mentioned in case anyone found it interesting and wanted to hear more. From Kim Prunty
AMMC = Antiquities Monuments and Museum Corporation, a non-profit entity that promotes the historic cultural resources of The Bahamas.
Earlier in the same Public Meeting they also talk about why they chose Lighthouse Point, Eluthera noting that they looked at several other locations nearby, including
Egg Island in Eluthera and
Morgan's Bluff in Andros and some locations in the
Berry Islands - and after initial EIA they didn't want to move forward with those because they would all require dredging and destruction of coral reefs.