Swimming Prohibited is a Genshin Impact Challenger: Series V Achievement that can be obtained by defeating the Bathysmal Vishap Herd without allowing them to dive into the water. It's a lot simpler than it sounds: you must defeat the two bosses at the same time to prevent either of them from jumping into the water.
How to defeat the Bathysmal Vishap Herd without allowing them to dive into the water in Genshin Impact
Start by heading to the Dainichi Mikoshi, where you'll find a hole in the ground that will lead you to the cave of the Bathysmal Vishap Herd.
The Bathysmal Vishap Herd consists of two bosses: a Hydro and Electro Vishap with separate HP bars. When you "defeat" one Vishap, it will jump into the water and continue attacking you from a distance. The only way to prevent one Vishap from jumping into the water is to defeat both of them at the same time.
You need to be careful which Vishap you attack to ensure that their HP bars go down at the same time. When their HP bars get too low, try to control your off-field attacks, such as Xingqiu and Xiangling's Elemental Bursts, Zhongli's shield, and similar attacks, which might accidentally kill one of the Vishaps too early.
Once both of the HP bars are extremely low, a tip is to wait until the two Vishaps are beside each other so you can deal the final blow to both at the same time. Alternatively, if your party isn't strong enough, you can enter Co-op mode and ask a friend to take care of one of the Vishaps for you. If you successfully kill both simultaneously, you'll get the Challenger: Series V Achievement called Swimming Prohibited.
To get more Bathysmal Vishap Herd Achievements, check out How to get the Hard Landing Hidden Achievement in Genshin Impact here on Pro Game Guides.
Nicki is a freelance writer with 5 years of writing experience. She's a fan of anything from HoYoverse, from Genshin Impact to Tears of Themis and Honkai: Star Rail. She also loves rhythm games like BanG Dream! and D4DJ.