Florence Bay is one of the quieter, family-friendly bays on Magnetic Island's north-east coast, reached by the rough Radical Bay Road beneath the Forts walk. The Marine Life Network describes it as one of the island's deeper sites, with depths of 3–15 m, a sandy beach, coral bommies and a rocky southern end with caverns and swim-throughs, and good fish life. The North Queensland Underwater Explorers Club highlights lettuce coral patches running parallel to the northern shoreline about 50 m offshore, inside a no-anchoring area, along with brain and staghorn corals in the fringing reef.

The northern end of the beach has good shallow snorkelling. The rocky southern end is the more interesting dive, with granite boulders forming caverns and swim-throughs. The bay also holds a wreck.

The motor ferry Magnet, which served the island, dragged its anchor in 1917 after striking a reef and was 'completely wrecked against rocks', according to the club's wreck index; its remains lie in the centre of the bay at about 9 m. Little is documented about what is left, so treat it as an added curiosity rather than a wreck dive. Like its neighbours, Florence Bay suffers from sargassum blooms in hot weather, and the club advises planning a visit for winter when macro-algae die back.

Early morning or late afternoon brings calmer water and fewer visitors. It is part of a Marine National Park green zone. For snorkellers and new divers, Florence Bay is a relaxed shore dive with more depth than most island bays, some structure at the southern end and a piece of island history in the middle.

Magnetic Island is reached by SeaLink passenger ferry from the Breakwater terminal in Townsville to Nelly Bay (about 20 minutes, frequent daily services) or by the vehicle ferry from Ross Street, South Townsville (about 40 minutes). Buses, hire cars and 'topless' mokes run from the Nelly Bay terminal to Arcadia, Horseshoe Bay and Picnic Bay. Florence Bay is reached by the unsealed Radical Bay Road from near the Forts walk car park between Arcadia and Horseshoe Bay; the road is often washed out, so check hire-vehicle conditions or come by boat from the Horseshoe Bay ramp (15 minutes).

A short track leads from the car park to the beach (about 100 m carry). Anchor on sand outside the no-anchoring area along the northern shoreline.

Magnetic Island's bays are sheltered from different winds depending on which side they face. The dominant south-east trade winds (15–25 knots, April–September) chop up exposed eastern and southern bays and stir up silt, so the island's best diving comes in the calmer months of August–December and on mornings before the sea breeze. Visibility is usually 3–8 m and occasionally 10–15 m; it drops sharply after strong winds, big spring tides and wet-season rain (January–April) when Ross River and Burdekin run-off discolour the water.

Dive at slack water, ideally high tide. Sargassum seaweed blooms in the hotter months can smother shallow reef flats. Marine stinger season (box jellyfish and Irukandji) runs roughly November to May – wear a full-length stinger suit or wetsuit with hood and gloves, carry vinegar.

Stinger nets are installed at Alma Bay, Picnic Bay and Horseshoe Bay in season. Florence Bay faces east-south-east and is exposed to fresh trades; calm days in the cooler months are best.

Snorkel or dive the lettuce-coral patches that run parallel to the northern shoreline about 50 m out, or head for the rocky southern end with its caverns and swim-throughs at 6–12 m. The Magnet remains lie in the centre of the bay at about 9 m.

No regular operator; independent divers and snorkellers, NQUEC club dives. Nearest dive centres for gear hire, fills and local advice: Pleasure Divers Magnetic Island, Adrenalin Snorkel & Dive.