The Jewel is a freshwater cave system in Crystal River, Florida, offering a significant vertical range between 7 and 96 metres. This site is reserved for advanced divers with cave certification and overhead-environment experience. Entry is via shore, leading into complex passages where visibility can reach 30 metres but may drop to zero if silt is disturbed. Divers must manage mild currents and potential surges throughout the dive. Due to the overhead environment, direct ascent is not possible. Precise buoyancy control is essential to prevent siltation and mitigate risks associated with deep cave exploration and potential entanglement.

Durney Key is an artificial reef and seagrass site located 1609 metres offshore from Crystal River. The site features shallow sandbars and seagrass beds with an average depth of 3 metres, ranging between 1 and 5 metres. Access is by boat only. Visibility at the site typically fluctuates between 3 and 7 metres. Conditions vary significantly, with water temperatures ranging from 16 to 32 degrees Celsius. Divers and snorkellers should be aware of potential hazards including boat traffic, cold water, entanglement, low visibility, rip currents, and surf. The site is suited for intermediate-level divers and snorkellers.

Hospital Hole is a submarine sinkhole located 300 metres from the shore in the Crystal River area. This site features a cavernous topography with depths ranging from 2 to 15 metres, averaging 10 metres. Access is exclusively by boat. Conditions vary, with visibility between 2 and 12 metres and mild currents. The water temperature fluctuates significantly throughout the year, ranging from 16C in January to 31C in July and August. The site is noted for being slightly warmer than the surrounding river, providing a thermal refuge. Hazards include boat traffic, deep water, low visibility, and overhead environments. Snorkelling is possible, though the site is primarily a cavern and cave environment.

Weeki Wachee Spring is a cave system located in Crystal River, offering diving and snorkelling experiences in a freshwater environment. The site features depths ranging from 6 to 14 metres, with an average depth of 10 metres. Divers and snorkellers can expect visibility between 18 and 30 metres. Access is via the shore, and the site is suitable for beginners, though it presents hazards including deep water, an overhead environment, and moderate currents. Diving and snorkelling are permitted in the main spring area by reservation only and must be conducted with a park-authorised dive shop or organisation. Facilities on-site include parking, toilets, showers, a rinse station, and a cafe.

Howard Park Sink is a submerged sinkhole and cave system located 183 metres from the shore near the causeway. The site features a combination of cave, cavern, and surrounding seagrass beds. Depths range from 1 to 23 metres, with an average depth of 12 metres. Conditions vary, with visibility typically between 3 and 12 metres and the potential for strong currents. Due to the overhead environment, depth, and potential for entanglement, this site is suitable for advanced divers. Shore access is available, and the area is also used for snorkelling. Facilities at the location include parking, toilets, showers, changing rooms, equipment rental, and a cafe.

Eagle's Nest is a submerged karst cave system in Crystal River, Florida, known for its extreme technical demands. The site features a shallow basin at 21 metres that leads into a vertical shaft descending to 95 metres. Divers encounter strong currents and variable visibility between 10 and 30 metres. Due to the significant depth and overhead environment, this site requires full cave certification and precise decompression planning. A thermocline is present, with surface waters warmer than the depths. Facilities at the shore entry point include parking and toilets. Divers must manage risks including nitrogen narcosis, entanglement, and decompression obligations throughout the 45-minute average dive duration.

Joe’s Sink in Crystal River is a freshwater cavern dive offering depths ranging from the surface to 18 metres. Divers enter directly from the shore into a system characterised by mild currents and visibility typically around 6 metres. The environment features dense aquatic plants, which present an entanglement risk, requiring careful buoyancy control and gear management. Divers should remain within the light zone and avoid disturbing the silt to maintain visibility. The site is suitable for beginners with an open water certification, though the variable visibility and cavern topography require attention. The habitat supports various freshwater fish and invertebrates, though specific species sightings are not confirmed.

Nestle Ledge is a reef site in Tampa Bay, Florida, offering a manageable environment for beginner divers. The reef structure spans depths between 3 and 15 metres, with an average depth of 10 metres. Divers encounter mild currents, which assist with buoyancy control while navigating the site. Access is strictly by boat, and the area experiences heavy boat traffic. Divers must deploy a surface marker buoy before ascending and remain vigilant of surrounding vessel activity at all times. Water temperatures fluctuate significantly throughout the year, ranging from 17 to 30 degrees Celsius, requiring divers to check current conditions and select appropriate thermal protection before entering the water.