boat train server mod

• Chain any vanilla boat or chest boat using the vanilla Chain item: click a boat to mark it as the lead, then click another boat to tether it behind. After each link, your selection moves to the newest boat so you can keep adding more cars for an infinitely long train.
• Boats keep a short gap, align to the direction of travel, and accelerate toward their lead so they keep up with a driven front boat.
• Sneak while using a chain on a boat to drop its current link and clear your saved selection; links also clear themselves if the lead boat disappears.
• Works on dedicated servers with vanilla clients—no custom items or registries required.
• Notes: selection is stored per player and resets if you change dimensions; long trains still follow normal boat physics (land and tight turns slow them down).