Greetings
The tides differences from Newport tides to the areas you questioned vary. Here's some ballpark figures:
Narragansett Town Beach along the beach ----about the same as Newport
Narragansett Town Beach at the mouth(Narrow river)---+ 1hour 30 min
Charlestown / Quonny Breachways along the Ocean Front----+ 45 to + 60 min
Charlestown / Quonny Breachways INSIDE----+2 Hours
Napatree Pt/Watch Hill-----+ 1 hour
Please note that these differences are sort of mean of both hi and low tide differences
Regards
Ray Bondorew-Author of "Stripers and Streamers"