Itacoatiara is the most popular beach in Niteroi. So it is nice to get there early to avoid the crowd on the sand. Things can get pretty crazy over there. The Beach is at the part of the Niteroi beaches that faces the ocean and it is pretty easy to get to since there are signs. Most of the time the best conditions happen when the swell is coming from east since that there wasn't a big south swell the last couple of days.
(photo: Google Earth)