ARK's base taming speed on PC, PS4, and Xbox is now doubled, meaning 1× is as fast as what 2× was previously. Dododex has been updated to reflect this. Use the "presets" dropdown for common multipliers.
For full Manta taming details, get the taming calculator app.
If you are planning on doing anything involving water prepare to despise these flat horrors. They can out swim you. They can swarm you. They can act friendly and once you turn your back eat your tame. Beware.
They have terrible turning circle, approach one from above and feed it. Then let it swim circles around you. The occasional time it gets close you can predict its attacks, it “bucks” just before the attack, which is the tail swinging underneath. Quick swim up or back avoids it. Be prepared to get dizzy, long time between feeding