aanker to the rescue!!! Thanks bud!
rein1705, when I say "a 'Date' problem", I'm referring to the game itself, which tracks dates a bit differently than you and I... They have February 29th, June 31, April 31, etc., as valid "Dates" in some of the game's config files, but the game itself does not recognize them. If something happens to occur near those dates, it can mess up your boat and / or home port, so it matters little when you start the game when one of those happens. You can also run into "Date" issues when one area of the game has an "upgrade" for equipment on one date, but it's set to a different date in a different area of the game.
The New Construction of course, does take out the issue of a previous boat, but since you've got the "Default Bow deck gun" mod in there, that can trash any game "default" in a similar fashion as moving it yourself. Rockin Robbins way is the easiest way to go, and then don't use the "Default Bow deck gun" mod. But aankers way can save your career, if you're deep into it. Read all that he linked to, and see if it's for you.