I fly those distances quite regularly, mostly over inland waterways..not too many times from the beach, using an
M2P...but NOT with the
SC. (It gathers dust on the shelf....too flaky, IMHO). I have never lost a drone in ~9 years, but I have donned my catcher's mitt for the return descent.

The
M2P is a very capable AC, but surfside winds shift more than it may seem...IMHO, one should do all their pre-flight setup with 1 battery, and then swap in a true 100% charged battery before flight. Ensure that you have triple checked all of your fail-safe parameters, i.e. RTH ALT, Low Batt alert, and warning levels etc....and cut your power budget by 5-10%, for good measure.
3 mile range is well beyond VLOS; Binocs do not qualify. When flying long distances over land, I have spotters down range, on VHF radio.
All the best!