navy nurse practitioners

I'm enrolled in the NCP and graduating in May. I have not been able to find out much about the role of nurse practitioners in the Navy. How many are there? How often do they deploy? What is their role on deployments? Are they stationed hospitals/clinics overseas? Where do they primarily work - clinics or hospitals or ships? My recruiter explained DUINS, but it sounds too good to be true. What is the payback for DUINS - 2yrs of service for every 1 year of school? I spent 6yrs as an enlisted members so I'm fairly familiar with how the military works. Anyhow, any information will be helpful. thanks