For the second straight morning, search operations for Interior Secretary Jesse Robredo and two companions resumed in Masbate early Monday.

Search teams readied to report to a beach resort used as a command center before 5 a.m., amid tight security, radio dzBB’s Benjie Liwanag Jr. reported.

The teams remain hopeful they can locate Robredo, pilot Jessup Bahinting, and co-pilot Kshitiz Chand, the report added.

Divers from the Philippine National Police, Philippine Coast Guard, and Philippine Army were joined by professional divers from Bicol, who were to alternate with them.

Underwater search plan

The government is deploying technical divers as well as underwater search techniques used last May when an Air Force trainer jet went missing off Mariveles, Bataan.

Jake Miranda, a technical diver familiar with both the Mariveles search and the current one in Masbate, says a side-scan sonar device is being employed to create images of large areas of the sea floor in the vicinity of the crash.

Once the plane's wreck is located, "then get the (geographical) coordinates, and bring down an ROV (Remotely Opreated Vehicle)," Miranda says via text, describing the plan. "When we have video, technical divers will go down."

GMA News' John Consulta reported Monday morning that the ROV is still being shipped from overseas.

Transportation Secretary Manuel Roxas II said on his Twitter account early Monday that the day’s search pattern will be based on sonar searches from Sunday night.

He also said a US plane with forward-looking infrared (FLIR) had also done flyby passes in the area.

Robredo, his aide Senior Inspector Jun Abrasado, Bahinting, and Chand were aboard a Piper Seneca plane heading for Naga from Cebu when the plane crashed off Masbate Saturday.

Abrasado was rescued by local fishermen and insisted on helping rescue workers look for Robredo.

President Aquino went to Masbate early Sunday to personally oversee the search efforts. He decided to stay overnight in Masbate.

On Sunday, search teams recovered a flight plan of the plane, along with debris from the ill-fated aircraft. –KG/HS, GMA News