I have a privilege to post a small entry into this excellent thread thanks to kind permission from Yqueleden (given to me some time ago).
History of insurgencies of muslim population of southern Philippines, first against Spanish, then Americans, Japanese and finally the Republic of Philippines is 4 centuries long and rich in notable episodes, also from naval point of view.
During one of outbreaks of unrest on Mindanao in 1890s Spanish military had to concentrate their efforts on the area around Lake Lanao
, which thanks being fed by four rivers and having shores convenient for amphibious landings, was simply begging to be used as a route of maneuver. Initially several improvised gunboats were used, but in 1894 designs for custom-made vessels, optimized for local conditions, were made by Manuel Rodríguez, chief engineer of Spanish naval forces in the Philippines. These vessels were 25 meters long and were characterized by a lightly armoured citadel with embrasures and gun ports for infantry assault detachment in the central part of relatively flat-bottomed hull. Two such vessels - General Blanco
were built in Hong Kong and delivered in sections to Mindanao in 1895. These were followed by two smaller and simpler ones - Almonte
in 1896. In theory, armament of all four was to consist of single Nordenfelt cannon and 3 machine guns, but in reality their armament seemed to be just "whatever could be found in the arsenal at the moment".
In late 1890s Spanish combat group made up of these 4 gunboats and several smaller boats and launches (and supporting unit of infantry) effectively cleared shores of the lake from insurgents, but the outcome of Spanish-American War sealed their fate and in 1899 they were destroyed by their crews.
It should be noted that some websites show a pictures of a smaller and simpler gunboats described as "Lanao", but I think these actually show either Almonte or Corcuera and term Lanao was originally used attributively, as in "some gunboat from Lanao area", rather than as specific name of the vessel in question.