I have a lvl 230 Castoroides called Wood machine. I initially thought I would only use her to get wood so I named her that. I latter found out that she was an excellent swimmer and can act as a semi aquatic mount. I didn’t have an aquatic mount so I explored the ocean with it. She could easily kill a megalodon or a pack of mantas. On my third ocean voyage with her I was killing a megalodon when a Cnidaria (jelllyfish) stunned her and forced me to dismount. I killed the Cnidaria and some Carnbonemys finished off the megalodon but Wood Machine was nowhere to be found. I whistled follow but no creature heard my whistle. I expanded my search area but still couldn’t find her. I was beginning to think that she died and I missed the death message. As I further expanded my search area I saw a few Cnidaria by the beach, so I killed them for revenge. After harvesting their bio toxin I looked up and saw a Castoroides with a saddle chilling in the middle of the ocean. It was wood machine! Turns out if you dismount a Castoroides underwater it will surface by swimming up along a straight line, and since I was kicked off fairly deep underwater she swam very far before surfacing. I would later run the lower south cave multiple times with her. My most recent mission with her is taming a basilosaurus, which is completely immune to the stun attack of Cnidaria. Time to massacre those stupid Cnidaria.