BR549 not only has the greatest phone #... he has the correct answer...
It's just like he said... but I will expand his answer a little...
Certainly you can take a houseboat out to sea - but only as far as Davey Jones' locker... Once there, (few, and I do mean very few ) ever come back.
Once you reach Davey Jones' Locker, you are home free... You can lay down your sextant, and throw your GPS overboard... as the bright lights ahead will guide you the rest of the way... Some say the houseboats are lined up bow to stern and port to starboard from one end of the horizon to the other... It is like a huge floating Las Vegas... only bigger and better... and I mean - we are talking "nautical square miles" of nothing but bars, floating hotels, floating casinos, floating prostitution palaces. Its like your wildest dreams come true... and no one cares how old you are, or who your Daddy is... You are in the middle of the ocean!
But your friend was only particially right when he told you there were "no laws". The truth is, there are no "police". But there are "laws". In the middle of the ocean "the laws" here are strictly enforced and tightly controlled and regulated by the Enosichthon family. And if you remember your Greek Mythology... Then you know these guys are kinda like a drug cortel - but only operate on the ocean. Today, because of the aging of the oldest brother - "Papa" Poseidon; most everything is controlled by the younger brothers: "Smack Daddy" Zeus, and "Hangin" Hades - and these guys can be brutal... I read somewhere that they have never "paroled" anybody.
So... What ever you do, you don't want to break one of "their" laws... They are the most feared by sailors, and these guys are so powerful it is said they can even cause storms and shipwrecks...
BR549 can tell you more about them.
Seriously... you can buy, build, or rent a houseboat... you can live on it in "navigational" waters... that means any water that flows to the sea... (most, if not all, land locked lakes - prohibit full time live aboards.)
Houseboats are NOT meant for taking out to sea... they are for inland lakes, rivers and safe coastal water as in the International Coastal Waterway (or ICW)
And, last, but certainly not least, there are laws everywhere... and yes, even the most serious ones govern your actions in the middle of the ocean.
Here is a better site to go to - to learn all about houseboats.
http://www.all-about-houseboats.com/index.html
Happy & Safe Boating!
PS. I don't know how old you are, and your comment or question regarding "no laws" in the middle of the ocean makes me think you are "very" young... or just maybe a bit immature... and we don't need anymore of that on the water... If on the otherhand you are serious... there is nothing wrong with your questions or dreams of living on a houseboat... It doesn't take a lot of "balls" to do it - as "Steplift" referred... (he just must not have any).
16 year olds have sailed the around the world... (in sailboats, not houseboats)... In fact, the very youngest teenager to do it was Robin Lee Graham... Fact is, another teenager (16 years old) just left California (within the last 10 days - I think) with intentions to sail around the world... this one is wanting to complete his voyage in 11 months.
So... whether living "on the hook" aboard a houseboat - or sailing around the world... one may take a bit more knowledge, skill and planning... but they both require an equal amount of responsibility.
So yours is a noble and respectable goal - but only if done for the right reasons.