Most of the ordered vessels - 71 short-range boats for coastal patrols and 27 able to go further out to sea - will be delivered this year, Bureau of Fisheries and Aquatic Resources chief Asis Perez said.
"This is just fulfilling our mandate. Our country has eight times more sea area than land area. We have 36,000 kilometres of coastline and over 7,100 islands," he told AFP.
"We need additional vessels. These (new boats) are actually short of our needs but this is all we can afford," he added.
Perez said his agency is also seeking funding to acquire 10 larger boats that can patrol the high seas.
Numerous Chinese fishermen have been arrested by Philippine authorities for allegedly poaching in disputed waters.
Similar incidents involving Taiwan have also occurred, the latest in May off the northern Batan islands when the Philippine coast guard attempted to arrest a Taiwan fishing boat only to be blocked by the Taiwan coast guard.
The moves come after a series of confrontations at sea between the Philippines and both China and Taiwan.
Tensions have been rising in recent years due to China's more muscular approach to enforcing its claim to most of the South China Sea, even up to the coasts of its neighbours including the Philippines.
Chinese ships have occupied a reef near the western Philippines since 2012 following a tense stand-off with Philippine ships.
