I couldn't find a working Forge mod that simply modified boats so that they don't break into planks and sticks. A problem that became increasingly frustrating in my survival world that utilizes water tunnels. This not only requires you to keep a crafting table nearby to get a boat again but they are so fragile that bumping a wall is enough to break them. 

This mod fixes that. Now placed boats become a "durable" boat, which behaves similar to the vanilla boat but with some additions that can be toggled on and off. 

Features:

• By default Boats will no longer break on impact. (no more planks and sticks. feel free to ram walls max speed! your boat will withstand.)

• Now using your empty hands or a tool you one shot the boat and it will instantly drop.

• The modified boat entity only exists while placed, when dropped it always give the vanilla boat item, this is to make the mod-safe to remove at any time.

• easyMobLoading (Can be turned on or off.) - This makes placed boats perform more like modern Minecraft boats, it will vaccum in any mobs/villagers within a 1 block radius for easy transporation. 

• preventFallDamage (Can be turned on or off.) - This makes boats act like modern Minecraft boats by removing fall damage to player while riding. Allowing you to use boats to safely scale heights.

Disclaimer: I don't know if this is the best way to approach this but it works and solves a niche problem for a niche version of the game.  I used several different Ai models to pull information and construct the mod. All tested by me. If the fact I used Ai bothers you feel free to ignore this mod's existence or even better make your own version without Ai (I would use it!)

This is a mod I personally use so I will likely be updating frequently, so I recommend always downloading the latest version.