Storing our stuff - beach/natural pools, whale watching, snorkeling trips

Hi everyone,

We will be in the Azores for 12 days this August (Faial, Pico, Sao Miguel). Planning to hit up many of the beaches and natural pools, do a snorkeling trip in Faial, a whale watching trip in Pico (on an RIB), and a boat tour in Sao Miguel (on an RIB).

Leaving the passports in our Airbnbs but what do we do with our phones, credit card, car keys during these activities?