- Southern Terminus:
- Sunrise Highway (NY 27) in Patchogue
- Northern Terminus:
- NY 25A in Mount Sinai
- 11.55 miles
North Ocean Avenue begins at Main Street in Patchogue and runs north as a two-lane local street to Sunrise Highway (NY 27), where it widens to four lanes and takes on the designation of CR 83. It runs north as a four-lane undivided road to the Long Island Expressway (I-495) at exit 63, where it widens to become a six-lane divided road. After a few blocks, North Ocean Avenue becomes Patchogue-Mount Sinai Road. There is a single grade-separated interchange at Bicycle Path, which is the name of a street, not an actual bicycle path. It then narrows back down to four lanes. For the remainder of its length, Patchogue-Mount Sinai Road is a four-lane divided highway with traffic lights at its fairly sparse intersections and a high speed limit of 55 MPH. It curves somewhat to the east to cross NY 112 and eventually ends at NY 25A in Mount Sinai.