Snorkelers interact with a Florida Manatee inside of the Three Sisters Springs in Crystal River, Florida January 15, 2015. On winter days, Florida manatees flock by the hundreds to the balmy waters of Three Sisters Springs, drawing crowds of snorkelers and kayakers to the U.S. sanctuary, where people may swim with the endangered species. But as tolerant as the gentle, whiskered sea giants can be of the accidental kicks and splashes of delighted tourists, wild life regulators want to ban most canoes and paddle boards and create people-free zones to protect the wintering “sea cow”. Proposed limitations for this winter are awaiting approval by the U.S. Fish and Wildlife Service. (Photo by Scott Audette/Reuters)

Stand up paddle boarders make there way across the waters of the Three Sisters Springs in Crystal River, Florida January 15, 2015. (Photo by Scott Audette/Reuters)

A sign welcomes visitors to the Three Sisters Springs in Crystal River, Florida January 15, 2015. Manatees can be seen in the background (L), taking sanctuary in an area off limits to people. (Photo by Scott Audette/Reuters)

Dive boats float by a protected manatee sanctuary and the entrance way to the Three Sisters Springs in Crystal River, Florida January 15, 2015. (Photo by Scott Audette/Reuters)

Gina Hall climbs down the dive ladder on her way to snorkel in the Three Sisters Springs in Crystal River, Florida January 15, 2015. (Photo by Scott Audette/Reuters)

Gina Hall (C) leans out to the catch the first sightings of manatees while on a guided tour with River Ventures in Crystal River, Florida January 15, 2015. (Photo by Scott Audette/Reuters)

A Florida manatee interacts with River Ventures' Captain Mike Birns in the Three Sisters Springs in Crystal River, Florida January 15, 2015. (Photo by Scott Audette/Reuters)

A Florida manatee swims by a snorkeler inside of Three Sisters Springs in Crystal River, Florida January 15, 2015. (Photo by Scott Audette/Reuters)

River Ventures tour operations manager Brandi Bruton gives the required orientation to guests before heading out to snorkel with the manatees at the Three Sisters Springs in Crystal River, Florida January 15, 2015. (Photo by Scott Audette/Reuters)

River Ventures tour operations manager Brandi Bruton gives the required orientation to guests before heading out to snorkel with the manatees at Three Sisters Springs in Crystal River, Florida January 15, 2015. (Photo by Scott Audette/Reuters)

Stuffed manatee dolls line the walls of the gift shop at River Ventures in Crystal River, Florida January 15, 2015. (Photo by Scott Audette/Reuters)

Novelty money featuring the Florida manatee are part of the numerous manatee branded items for sale at River Ventures in Crystal River, Florida January 15, 2015. (Photo by Scott Audette/Reuters)

Florida manatees swim in the Three Sisters Springs while under the watchful eye of snorkelers in Crystal River, Florida January 15, 2015. (Photo by Scott Audette/Reuters)

A manatee calf nurses from its mother inside of the Three Sisters Springs in Crystal River, Florida January 15, 2015. (Photo by Scott Audette/Reuters)

Observers count the number of people and manatees traveling in and out of the the Three Sisters Springs in Crystal River, Florida January 15, 2015. (Photo by Scott Audette/Reuters)

Along with counting manatees and humans inside the Three Sisters Springs, researchers take regular temperature measurements throughout the day to better study why the manatees flock to this area in Crystal River, Florida January 15, 2015. (Photo by Scott Audette/Reuters)

A Florida manatee swims in the Three Sisters Springs while under the watchful eye of snorkelers in Crystal River, Florida January 15, 2015. (Photo by Scott Audette/Reuters)