Just before getting to the launch area I passed a fenced off side steam on the right. (See map). This was the entrance to Blue Hole Spring.
I stowed my boat and gear and went up the path towards the pic-nic area and found a trail which went to the Blue Hole Springs. This is a popular spot for swimmers, snokelers and divers. Quite impressive.
The spring forms a lush pool in an area of deep forest and floodplain. The spring pool is about 75 by 120 feet wide. Water flows powerfully from a cylindrical limestone shaft near the center of the pool.
The shaft is about 12 feet in diameter and 6 feet below the surface. It extends down 15 feet before opening into an underwater chamber with a depth of around 35 feet. There is a cavern system associated with the spring.
Water in the spring is clear and can be an intense blue. The rest of the pool area is covered in eel grass and about 6 feet deep. Cypress trees encircle the spring, which is also fed by the run of Cedar Head Spring, which flows into the Blue Hole Spring from the north.
Source: Spring Fever