Inviting blue beaches only scratches the surface of why the Port's waterways are so popular.
Dive down a little deeper and you will enter a world filled with fascinating marine creatures like the nudibranch, also commonly known as sea slugs.
The Combined Hunter Underwater Group (CHUG) are preparing to host its 25th Sea Slug Census on November 28-29 where citizen scientists will dive, snorkel or walk around the Bay's rock pools to photograph and document sightings of nudibranch.
"Nudibranch are certainly eye-catching. They come in all shapes, sizes and colours," CHUG chairwoman Margo Smith said.
"They help build people's curiosity about the marine environment, which is important. The more people interested in our marine environment, the more people will protect it."
Since the first Sea Slug Census in 2012, more than 250 species of nudibranch have been recorded.
Snorkelers, divers and people who like to look in rock pools around the Bay are being invited to take part in the census. Register and receive instructions by sending an email to email@example.com.
Participants are asked to search for and photograph nudibranch seen within a time frame across the two days, which CHUG collates into a report. Data collected during the census helps inform further research.