As of noon Friday, the echo sound equipment lent by fishing magnate Merfin Tan of General Santos City's San Andres Fishing, arrived in Davao City on board the B205A-1 rescue helicopter of the Philippine Air Force (PAF).
The echo sound equipment, which is used by Tan in the operations of his fishing company, can reach depths of up to 400 fathoms or an equivalent of 2,400 feet.
The equipment earlier used by TF C-130 is the sonar equipment of diving enthusiast Carlos Munda, which is capable of reaching depths of up to 1,000 feet only.
The first day of the rescue and retrieval operations, which lasted Tuesday, saw fishermen, seaside residents, and volunteers from all walks of life scouring the shores from Agdao to Bucana in Davao City.
On the second day, boat owners lent their private crafts and divers set up their equipment.
But with no means to find the exact location, as it is believed the plane could have dropped in the deep part of the gulf going south, nothing much could be done but to scour the beaches and the water surface again for debris.
Light drizzle greeted the fourth day of the search Friday, with search and retrieval teams returning to the Task Force C-130 at Sta. Ana pier empty handed.
Only a left piece of military charol shoes, airplane foam, and a piece of metal believed to be part of the interior of a C-130 were the things recovered as of Friday noon.
Six navy sea crafts were deployed Friday morning to conduct search and retrieval operations in the various parts of the Davao Gulf. One was deployed to sweep the area of Peñaplata to Talikud Island in the Island Garden City of Samal, while another was tasked to sweep the shorelines of Davao City from Panacan to Mansaca Point in Panabo City.
Another sea craft was deployed to run through the coastal area of Davao City to Tibungco district, while another vessel was checking on the coastal area from Panacan to the Talomo area.
It has been said that the US government will be sending in one of its vessels to speed up the search and retrieval operations for the missing aircraft.
Contrary to reports by a major television network, the exact location has still been not confirmed by TF C-130 as of Friday.
