Center tip: as they have added the mosa to the center I've found the easiest way to knock one out is find one close to the bubbles get its Agro and swim in the bubble the mosa will get stuck and it can't hit you. Also this gives you unlimited oxygen and sanctuary from being attacked by anything else. 🤘🏼

If you have 300+ oxygen they are relatively easy. Take advantage of their bad turn radius and stick close to their tail to KO.

These can be tamed by aggroing them and swimming upwards. There is a height barrier which they cannot cross and so you can tranq them with a crossbow from above that invisible barrier.

Underwater caves are very helpful for knocking these guys out. Always bring extra tranqs as this thing is basically the giga of the sea and torpor drops very fast.