Hanna said it would be unusual for someone to enter an adult lion's cage without another person accompanying them or close by.

CNN: STORY HIGHLIGHTS

Hanna said it would be unusual for someone to enter an adult lion's cage without another person or with someone close by.

CNN: Lion kills worker at sanctuary in California

She's in the water without a shark cage, relying on electronic shark repellent and a team of divers to keep them away.

CNN: August 20, 2012 -- Updated 1157 GMT (1957 HKT)

The following year, she completed what remains the longest swim in history without a shark cage: 102.5 miles from Bimini in the Bahamas to Jupiter, Florida.

CNN: Nyad delays attempt to break distance-swim record

Speaking of sharks, Nyad is attempting the swim without a physical shark cage, and she is relying on an electronic shark repellent device and a team of divers to keep them away.

CNN: Diana Nyad making fourth attempt at Cuba-to-Florida swim