Water giga, carries base, need I say more

Great Dino to use doing underwater drops perfect for you collecting those wooden shields and shield bp that completely waste you time.

I very recommend finding a good crossbow first a journey or higher

Great all around underwater. Powerful and tanky. I have noticed they are able to survive a jelly fish swarm. I have mine kill around 40 jelly fish while being shocked.

I recommend pumping health and melee.

DO NOT CRYO POD WITH STUFF ON THE PLATFORM SADDLE, IT DESTROYS EVERYTHING. IT ALSO HAPPENS WITH OTHER PLATFORM SADDLES.

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

DONT FIGHT JELLYFISH WITH THESE I made this mistake and my 261 mosa died.

Here is how to tame this guy, prepare lots of tranq arrows in a crossbow, then build a simple trap that works or if you wanna save resources, you can shoot it from an underwater resource cave or do it like a bronto as they are pretty slow. Once it's knocked out put narcotics or in it's inventory and exceptional kibble which worked best for me and you will have to wait. Once it's finished taming you can either slap a saddle or a platform saddle on and bam you have the giga of the ocean

When I found a low level 4 more spawned with 1 being alpha and it was level 100 with 164,375 hp and I was on the easy preset

Not sure if its just my game on ps5 but just in case, I finally found a Mosasaurus, and then a few more. All of them were trapped in underwater rocks. I could only see the tail or their smiles. Just a tip if you're having trouble finding them. Since already trapped, I just tranq'd and used cryo to take them with me. Hope it helps.

A max level, imprinted mosa with a high armor saddle is virtually unstoppable. I had a green one that I bred and named Jormungand after the world serpent in Norse mythology. It’s strength was mythical! (No pun intended)

A good way of looking for these things (mobile): sweep the border of the map and the ocean floor, using an ichthy to keep everything away. Once you find one, park your ichthy somewhere, then swim up to the depth limit of the mosa (you might have to test where it is though, be careful, mosas can swim up FAST). Being off the ichthy will catch its attention. Swimming up to the depth limit will cause it to Aggro off of you, so go back and forth with going to its depth limit, attracting it, and swimming back up to fill it with tranqs. The basic idea is attract, swim up, fill with tranqs, repeat. Hope this helps!

My mosa has 37k health and over 600 melee, I fear nothing in the water

i tamed a lvl 145 x mosa with 600 arrows and 6.5 crossbows today

NOW THAT YOU HAVE TAMED YOUR UNDERWATER GIGA, ENJOY DESTROYING UNDERWATER TEK TIER BASES. ;)

I tamed one with a mastercraft crossbow and about 5-10 tranq arrows and around 90-100 bio toxin and some prime fish meat but it was only a level 15 or 16 use a bronto or a good berry harvester and just kill a Rex or something fro prime meat that spoils pretty fast I just killed an alpha raptor and then tame something like an archelon for bio toxin and then just tranq it out and give it extraordinary kibble, raw prime meat, or raw fish meat (regular fish meat and regular meat works too but it is not good and only does 8% taming) and then you have a mosasaurus.

These creatures in real life actually needed to surface to breath much like whales, also they stayed near the surface of the water, never straying to deep.

Close you eyes and count to ten, or swim upwards

Giga but in water, you see , you run

My mosa has 14K HP and over 300 melee with an acendent platform saddle and he can kill anything in the ocean. Even alpha Mosasaurus and still have 13K health. (I play mobile.)