Some 20 vessels and aircraft are engaged in the search covering 3,900 sq nautical miles of sea, including 750 sq nautical miles of water off Miri, that has entered its sixth day today.
Malaysian Maritime Enforcement Agency (MMEA) Kota Kinabalu director First Admiral (Maritime) Adam Aziz, in giving the breakdown of the vessels and aircraft engaged in the search, said the agency had deployed four ships, a boat and an aircraft.
The Royal Malaysian Air Force deployed an aircraft while the Royal Malaysian Navy sent an aircraft and four vessels, Adam said at a briefing for reporters at the MMEA operations centre in Likas.
He said Marine Police had deployed four vessels and the Royal Malaysian Police were using two aircraft in the search.
Adam said Brunei Darussalam had also deployed a ship and an aircraft to conduct a search in its waters.
The catamaran, with the 28 Chinese tourists and three crew members on board, capsized at about 10am on Saturday after being battered by strong winds and high waves an hour after leaving the Tanjung Aru jetty here for Pulau Mengalum, 56km northwest of Kota Kinabalu.
Twenty of the tourists and two crew members were rescued and three tourists were found dead, leaving five tourists and a crew member still missing.
Adam said the search by the vessels went on round-the-clock while the aircraft left for the search area at about 7.30am.
Asked about a request from the Chinese embassy that a search be conducted on the sea floor, Adam said it could be done once the location of the capsized boat had been ascertained.
He said although there were eyewitness accounts that the boat went down about eight nautical miles from Pulau Mengalum, the possibility that currents dragged the vessel to another location could not be ruled out.