This is single player game, no support for multiple players.
What can be improved
For simplicity, I specified the formula in one column containing all tiles (8x8x2). Grouped columns has some gap in between so the boat doesn’t look nice. this is now fixed
Better score tracking in general, leadership board, etc.
Better UX in general
Known issues
Unplacing is undefined when you place two overlapping boats on top of each other, you can unplace all to get back to the normal state.