(On top because of convinience)
Do i recommend this? Really hard to say as this title is so very different. If you want some underwater action or competition or a challenge then this is as wrong as a game could be.
If you like a total relaxing chill from time to time without the slightest pressure at all, or simply like diving (although this is by no means a diving-simulator!), this one could be of your taste.
Can you even call "World of Diving" a "game"? There is no real goal, no enemies, no story, no threat, not even the fear of running out of oxygen and no deeper meaning at all.
You just go, well, diving and do, well, diver-stuff.
For that you have some tools at your disposal like the Metal-Detector (for finding gold), the camera for taking photos (you don't say!), the diver propulsion vehicle (DPV) for getting around faster.
On each map (there are around 9 at the time of writing) you can do some missions or even "challenges" (some with, some without a timelimit) for which you'll get some gold. These missions consist of stuff like "photograph these 3 fishes" and the likes.
Also there is a mission-editor which lets you create your own stuff, and on each map you could do missions others have created.
What is the purpose of all this you may ask? Consider this game a total relaxing chilling "game". You don't have to race time, there is nothing to win, you can't even fight anything and nothing will hurt you either.
And you can even do this online with others (there is no chat, you'll have to communicate with handsigns. Nice idea). But to keep you mildly motivated to relax even more, there is a progression. You will get XP for missions
which will "level" your character. The higher you'll get, the more stuff to equip your character will be unlocked. Among those are e.g. cute companions like a clownfish or even a shark.
But there is a dark side too. An itemshop. Yes. An itemshop for a totally non-competitive game :-)
Right now these items are all of cosmetic nature and you could get the bought items by collecting too (which of course will take much more time). Still it leaves a bitter taste for the critical customer.
One thing to really judge in this title are the graphics: Really fitting, nothing next-gen but still beautiful. Yet quite demanding. With my rig (see profile) i won't get higher than 30-60fps on Ultra with FullHD.
But OK, it's early access, and if you're fine with lower fps that is totally acceptable for a title like this.
BTW it supports Occulus Rift, but no 3D-Vision yet (DarkStarSword, the holy knight of 3D-Vision-fixing is working on a fix though).