Travis Deel, 39, is assigned to the USS Philippine Sea.
He was arrested July 17 in Sarasota County, which is more than 260 miles away from where he lives on the base, authorities said.
Authorities said Deel met the agent, who was posing as a teen, on an online chat site.
They exchanged phone numbers and began texting, the incident report said.
The agent told Deel she was 14 years old.
According to the report, Deel responded he “never did anything like this before, especially with someone your age.”
Investigators said Deel said he was aware he was talking to a teen and that he was nervous he could get in trouble.
The conversation turned sexually explicit when Deel sent a nude picture of himself to the teen, the report said.
Following his arrest, Deel told investigators he purchased condoms at the Navy Exchange before driving to Sarasota.
Deel pleaded not guilty to three felony charges. He’s expected to appear back in court Aug. 23.