I think that this post was revolutionary because it was so clear and it fit in so well with vanilla minecraft. I was hopeful in 1.6, 1.7 and now 1.8. It seems that they are slowly working to it and I hope that they add it. Until then we have slimeblock boats.
I definitely agree! Support Modular boats! I love the chest idea, and the sails, but let's keep it in the spirit of mine craft and not use and engines. Sails are nice, maybe oars on smaller boats? I think rather than cannons, there should be some sort of mounted crossbow. Maybe I'm wrong but it feels like engines and guns are too modern for mine craft. Oh and don't forget grappling hooks!
PS. I also think that boats should be custom designable, up to a certain size. If anyone's interested PM me and I'll share more details.
Bigger boats seem more fun, but we're looking at lots of collision detection and special mechanics for placing blocks. Alternatively, we could have the ability to build boats block by block, but that will require lots of collision detection as well or be restricted to cardinal directions.
Ropes. Crafting formula would be 3x2 with String.
Ropes will be a double edged sword. Enemy ships can use ropes to connect to your ship and invade it. Probably need grappeling hooks for this, but I dunno what formula would be suitable.
It can also be used by a player to make a fleet of interconnected ships that will be harder to sink. When connected, all connected ships will either die together or sink together. If the number of ships with no HP is more than half, all the ships have 2 minutes before they sink. If enough ships are fixed in that time period, the sinking will end. However if lets say 4 out of 10 ships have no HP, the other six ships are keeping them from sinking. Ropes can be cut with shears.