Pointless Boat Suggestions.

[SteamMonkey]

I have no doubt this is way too early in the process to be making boat suggestions. Given we're only in the framework stages of the new content, I'd be willing to bet there's already a LOT on the whiteboard back at Klei that we'll be seeing "soon". However... that doesn't mean I'm not thinking about this stuff and wanna post some ideas. At the very least, if we have similar ideas to Klei it'll validate their idea for them internally and there's a chance our ideas can inspire them to make adjustments to existing plans or add to existing plans. 

Hulls: 

Reinforced Hull: higher health and/or reduced damage on impact (potentially negated by mechanic below)
Aquadynamic Hull: Smaller, faster, reduced HP or "armor". (potentially negated by mechanic below)
The Barge: Large hull, slower but double sized, double HP and/or half damage on impact.

Masts:
The BOGO Sail; Build one, get one. Has 2 sails. Get it, ehhh, get it? Has double she speed impact of a regular mast. 
The Crows Nest: Mast with a bird cage on top. Why? Because...it's funny. 
Artificial Wind: Craft with 5x Luxury Fans, is a mast that looks like a windmill made of giant feathers. Dramatically increased speed but requires 1 player to steer the wheel and another player to 'crank' the windmill. (mechanically this can use the 'paddle' mechanic where hte player clicks on the windmill repeatedly, the direction is just controlled by the steering wheel)

AddOns:
The Hold: 12 slot built in storage, looks like a trap door, nothing can be built on top of it. 
The Poop Deck: Advanced Farm on a boat with a different texture.   Combine this with the Crows Nest and you can grow dragonfruit and get that vitamin C you need while taking those long journeys.
Captains Quarters: Tent on a ship with a different texture. Has "uses" like a tent but doesn't disappear when it's out, can be repaired. 

Supporting Structure:
Dock: Expensive to craft. Boats do not take damage when they run into them. 

Mechanics: 
Repairing the boat should be fixed obviously. It's currently buggy as heck. I"m sure you're already on it. 
"turfing" Hulls. Allow certain turfs to be placed on boats and 'reskin' them and change their attributes. Turfs can be pitchforked off but do 75% damage to the boat if you do. Having these as options would negate the need for the Reinforced and Aquadynamic hulls. 

• Cobblestone Turf: Boat becomes immovable but indestructible.
• Scaled Flooring: Doubles durability
• New Turf: Ruins Turf. Looks like Ruins floor, requires Thulecite and Nightmare fuel. can be placed in the world or on the boat. While on this turf you have a constant sanity drain of X/min (devs choice).
• Moon Crater Turf: Doubles the speed of the boat.

The obvious desire with cobblestone turfing is to be able to build bridges and/or water bases. The new Ruins Turf is designed expensive but will offer you a place to go recover while exploring the islands once you've managed to jump into the caves and get some stuff to make it, it also adds a turf to the game that would be useful for nightmare farming in long standing worlds.

[SteamMonkey]

Additional point on Docks: 

These could possibly take damage instead of the ships so there was still some consumable nature to the ship landing and incentive to not just barrel into them.