Hey guys. I started this project out by finding a very very small island and digging down until i got under the sea, but i'm not satisfied with that anymore. So I am going to complete my goal of building an undersea glass house (with magma lighting of course). So here's how i'm going about it.
For some reason it won't let me attach a screen, so i'll describe it.
I started by mining out most of a beach to get the from it. The sand is key. What you do is you start building sand around the edge of your island, but what will happen is the sand will sink to the bottom. build it up to the surface of the ocean. this will fill in the ocean, deleting the water there. You can then mine out the inner layers and reuse them, expanding the basin you have made for yourself.
Eventually i'll get a large enough lot and i will be able to build my paradise and then fill the ocean back in.
Another tactic is to place a ladder deep under water. Ladders displace water, so you can literally carve out an air bubble anywhere you want. Kind of hard to see unless you make a large enough area to add torches.
For some reason it won't let me attach a screen, so i'll describe it.
I started by mining out most of a beach to get the from it. The sand is key. What you do is you start building sand around the edge of your island, but what will happen is the sand will sink to the bottom. build it up to the surface of the ocean. this will fill in the ocean, deleting the water there. You can then mine out the inner layers and reuse them, expanding the basin you have made for yourself.
Eventually i'll get a large enough lot and i will be able to build my paradise and then fill the ocean back in.
http://www.minecraftforum.net/viewtopic.php?f=1&t=23440
Anyway i will work on gettin screens up when i have enough time.
Search youtube for some more ideas