Just a few questions; thanks in advance 
Does Andoweem have an ocean? If so, how can I find it? I’ve been wandering around the planet for a while with no luck
How do you manipulate water and lava? Do you pick up a source block in a bucket, or is it limited to whatever’s available in nature?
Is there a guide to mining gems? I know that you have to mine close to mantle underneath a desert biome on Andoweem to have better chances of finding diamonds, but what about the other gems?
Doing some searches in the forum will bring up a lot of answers to many questions.
I’m not sure about an ocean on the planet you ask but while on any planet you can enter the sanctum and look up to see the planet. Watch it for a while and it will fully rotate around showing everything.
Water/Lava has a source block in like each block. Once removed it is not replaced until regen happens. We cannot pick anything up yet in buckets like Minecraft. There are a few other dynamics with how it works but overall Minecraft stuff has not been implemented. No ETA on when.
There are many gem posts out there… this has a lot of helpful info - MEGA THREAD: Gem Locations (After March 2017 Resource Distribution)
According to boundless-maps.com, credit to @Simoyd, there are a few lakes on andoweem, but nothing huge like an ocean.