1. Don't shoot their head, shoot their butt or body. (This is true, dont trust gamepedia)
2. It wont left deep sea, so u can easily stay out of deep sea border and KO them.
3. Make sure to kill everything else around it before start to K.O it.
Very easy to tame if you know what your doing. First tame an Ichthyosaur. Then grab a crossbow and some tranq arrows and find one and knock it out. It is not be able to attack if you are on the Ichthy. As you are taming it, be sure to remain on the Ichthy unless feeding narcs, so other creature don’t hurt you. Vote up if this helped
Bring more tranq arrows then you think! Mine took 100 at close range, on the body, at LEVEL 3.
I took cooked prime meat (stays better longer) and got mine in only four feedings. On an icthy they don’t chase (mobile player here) happy taming- Survivor Belle