I though the Dolphin level starts with 10k HP. But i was wrong so i am already now a Dolphin with ~ 6K HP. I am not sure if i will be able to reach any higher level. I just read this post https://www.publish0x.com/behiver/the-fish-types-in-the-hive-blockchain-sea-xpzgvvn and > 56k seems to be a real long way. But well a few years ago i would not expect me to become a HIVE Dolphin.
I am currently on holiday and this was just a nice surprise. I hope you are all enjoying sunny days!