NDBC 44063
Neptun covers NDBC 44063 (United States) through the NOAA NDBC network. One GET request returns its readings as JSON — in the same shape as every other network Neptun serves, so you write the parsing once.
Source: NOAA NDBC · Position: 38.9630, -76.4480
Request
curl -H "Authorization: Bearer mapi_YOUR_KEY" \
"https://neptun.marine-api.com/v1/levels?lat=38.9630&lon=-76.4480&radius=5"