Directions - Located at the idyllic holiday location of Hamelin Bay, just north of Augusta, head towards Caves Road and keep driving south until you see the signs for Hamelin Bay. There are two car parks for the main beach but these will fill up quickly in the peak summer holiday period. Mushroom Rock is a 500m swim offshore from the boat ramp, just look for the smaller rock formation to the right of Peak Island (fourth picture in the below gallery).
The Snorkel - With summer holidays usually meaning a break from hiking and a focus on cycling and snorkelling, I scheduled in a week down south to tackle some more snorkelling spots I had been eyeing off since my visit last year. One destination that I've always been fond of and knew was a good spot thanks to the sheltered nature of the area was Hamelin Bay. Armed with an old copy of CALM's Dive & Snorkel Sites in Western Australia (3rd Edition), I flicked through the pages and found that Hamelin Bay had an offshore reef formation that sounded pretty cool.