The Pokémon Go Spelunker's Cove event is live, and you can participate for a limited time to see the handful of exclusive spawns that appear. Those who want to get more out of the experience can purchase the Beach Bash Timed Research.
Adventure Week Premium Timed Research & All Collection Challenge Rewards Pokemon Go | Shiny Amaura
It's important to note that the Beach Bash Timed Research is a paid ticket: you must purchase it before you can start earning these rewards. You can purchase them directly from the Pokémon Go in-game store. Unlike Special Research tickets, Timed Research has an end point. We recommend purchasing this ticket early in Spelunker's Cove if you want the full rewards.
Here's how to complete the Beach Bash Timed Research in Pokémon Go.
The Spelunker's Cove event runs from June 15 at 10am EST to June 18 at 8pm EST in your local time zone. It gives you a full weekend to complete all five tasks for the Beach Bash Timed Research, which should be more than enough time.