The IT Intrepid appeared off the Coastsider earlier this week. According to Pillar Point Harbor staff, the vessel was a cable laying vessel under contract to the Navy. The cable in proximity is the Pillar Point to Pioneer Seamount cable that was used to power sonar used to study temperatures in the oceans. It was also rumored to have been involved in the secret high energy sonar experiments that were believed to kill porpoises and whales.
Detailed information about the cable mission can be found on NOAA's website.