Aram Boghosian for The Boston Globe

Harvey Duplantis, a marine operations engineer, readied a Bluefin-9 unmanned underwater vehicle for a demonstration.

Aram Boghosian for The Boston Globe

Ben Pelletier, marine operations engineer, also worked to prepare the Bluefin-9.

Aram Boghosian for The Boston Globe

An unmanned underwater vehicle was shown recently during a demonstration at Bluefin Robotics in Quincy.