Two small island provinces, two different hazard pictures. Camiguin is volcanic with steep ground; Siquijor is smaller and mostly coastal. Here is what to screen, and where the mapped data thins out.
Siquijor and Camiguin are small, popular, and increasingly bought into by people from elsewhere. Both reward a careful screening, and both show the limits of national data more clearly than a mainland address does.
Camiguin is built from volcanoes, and Hibok-Hibok is on the PHIVOLCS list of active Philippine volcanoes. A hazard screening reports the distance from your address to the nearest mapped active volcano, and the active volcano brief explains what that distance is and is not.
Two things to be clear about:
On steep volcanic slopes, also read the slope value together with mapped landslide susceptibility.
For most Siquijor addresses the important lines are the coastal ones: storm surge read together with elevation, plus mapped flood exposure and the distance to the nearest mapped waterway on the low ground behind the shore.
Distance from the water alone is not the answer. Height behind that distance is half the story, which is why the two lines belong together rather than apart.
This is the honest part, and it matters more on small islands than anywhere else.
National datasets cover the country, but coverage is not uniformly dense. Features like waterways come from open mapping that is more complete in cities than in remote areas. If a report shows no mapped waterway near a small-island address, that is a statement about the map, not a guarantee about the ground.
So: treat an absent feature as a prompt to verify, never as an all-clear. Walk the property, find the channels yourself, and ask people who have lived through a bad season there.
Much of the land changing hands on both islands is bought to build something guests will stay in. That adds two responsibilities that a family home does not carry.
You become responsible for people who do not know the place. A guest cannot read the sea, does not know which road floods, and will not know where to go. Whatever the site is exposed to, you inherit the job of having a plan and communicating it.
Coastal building has rules that are not on any hazard map. Setbacks from the shoreline, easements along waterways, and environmental requirements are handled by national agencies and your LGU. A screening tells you what the ground is exposed to; the municipal planning office tells you what you are allowed to build and how close to the water. Ask them before you design, not after.
On a small island the most valuable information is held by residents, not datasets. Ask:
Building on an island is slower and more expensive than on the mainland, because materials arrive by boat and trades may come from elsewhere. That means a hazard you would shrug at on Luzon, because fixing it is a phone call, deserves more caution here, where fixing it is a logistics exercise.
A hazard screening reads public national datasets at your coordinates. On small islands it is a good first filter and a poor substitute for local knowledge, because it cannot see wind, water supply, ferry reliability, or features that were never mapped in the first place. Use it to narrow the list, then spend time on the ground.
CheckHazard does not replace a professional geotechnical or engineering survey.