Part 121.
FAR Section 121.161
Operating under part 121, to remain non ETOPS, a TWO engine aircraft must not operate outside of 1 hour (430 NM for the 319/320) of a suitable airport (not shoreline - shoreline determines over water criteria - ETOPS and overwater are two separate issues.)
(OP was regarding a two engine airplane)
An aircraft with more than two engines can operate up to 180 minutes from a suitable airport and remain non-ETOPS.
Take care.
Last edited by CaptainMongo; 17th April 2016 at 14:05.
Reason: Added more than 2 engine info