The Ships Mod, by Cuchaz, has been in full swing for quite some time, but if you have not had a chance to check out this remarkable bit of engineering, it's definitely worth a look!
The premise is simple: build a ship using blocks, then set sail on it! The mod uses physics not unlike the ones that allow vanilla boats to float, and so it is possible to make something too heavy, unbalanced, or just plain strange enough that it can't sail. On the other hand, some players have made some truly mind-blowing recreations of actual ships that sail well, including galleons, and even some submarines.
The mod has a lot of nice little touches as well. For example, as long as water is not coming over the sides, you will not see water blocks in your ship, even if the body of it is below the water line! Ships puts a lot of detail and attention in to make the experience enjoyable, including upgrades, tiers of building, and quite a bit more. If you are ready to set sail on something bigger than a canoe, be sure to give it a try.
Ships is currently for version 1.7.10, and can be acquired right here!