I don't consider that Ocean County is really 'South Jersey'. It's in the New York CSA and has the most culturally in common with Monmouth. One argument in favor of its being part of South Jersey is that it contains parts of the Pine Barrens, but all things considered I just don't think that really means as much as the CSA divisions or the nature of the Jersey Shore.
Came here to post exactly that. Mercer County, actually, has a better claim on being "South Jersey" if one splits things in a way that's historically correct (East/West Jersey) and respectful of the NYC/Philly split. And, yes, I know that it's kinda fuzzy around the edges, Princeton is more North while Tuckahoe is more South, but for the
most part Mercer is further "south" than Ocean.