I'm very grateful for your reply, but for this mod the files look a little bit different than for New Horizons. No mention of OPEN_SEA_MOD in there.
I apologize. I'll get back to you once I find anything. Meanwhile, please consider joining Buccaneers Reef discord channel: https://discord.gg/Ps3zMtP
ChezJFrey and other people who might be able to help are online and active on there.