The "Victoria's Chinatown" Adventure takes you to five locations around Victoria's historic Chinatown. After you complete each of the five locations of the Adventure, you'll be given part of the coordinates to this bonus cache. There's nothing at the posted coordinates, so you don't need to go swimming. This cache isn't in Chinatown, but is less than 15 minutes of walking from the Adventure area.
Instructions: After you've completed the Adventure, go back in to look at the journal and scroll to each entry to get the pieces of the coordinates. This bonus cache is at:
N48 AA.BCC W123 DD.EEE
You'll need to have the "Adventure Lab" app installed on a mobile device in order to complete the Adventure. Links to download the app from the Apple App Store or Google Play Store can be found here: Adventure Lab app
The Adventure can be accessed here: Victoria's Chinatown Adventure Lab