There are some shocking realities of living on an island chain created by a volcanic hotspot. When making your decision to live in paradise, you also accept additional adventures and risks, and we would rather you be informed ahead of time.
There is the reality that some homes need Volcano, Tsunami, Earthquake, Hurricane, and Flash flood insurances. However, the hazards are acknowledged but not overly feared, much like tornadoes in the Midwest or earthquakes in California.
The Hawaiian Island chain extends far beyond the islands we see, created by the volcanic hotspot which the continental plate continually moves over, which presents a unique series of hazards.
Creator of Vog (see Climate tab), Lava tubes, black-sand beaches, and has the ability to (at a snail's pace usually) wipe entire towns from the island. If there is a current flow active you can find out more about it at the USGS Hawaiian Volcano Observatory.
We may not be on a fault line, but we are slowly moving off the hotspot and are living on an active volcano. As such, the earth tends to shake every once in a while.
We living in the center of the Ring of Fire (which extends around the Pacific Rim). The edges of this tectonic plate move and have earthquakes, which give us tsunamis. You will see signs around town which direct you to higher ground. Bear in mind we have monthly testing of the sirens (1st work day of the month). In the event of a tsunami there will be several hours before the wave arrives, and today's technology can tell how big the waves are as they come.
From June to November we have hurricane season, Iselle in 2014 took out a fair amount of trees and hit Pahoa. Usually they get drawn north of us, which can cut of trade winds and make things really humid for a week, or we get the outskirts of the system and rain dumping on us. It's usually surprising when it hits, and Hawaiians tend to be more relaxed than say Floridians when it comes to boarding things up and hunkering down.
Remember that 126.69 inches of rain per year? Sometimes it comes a fair amount faster and can be a problem for neighborhoods.
Go with a local; they will know the safe swimming and jumping spots. Remember those lava tubes? They are networked under the island, and you can get sucked into them if you jump into the wrong spot in a river.
Illnesses to watch out for
Dengue Fever - Mosquitos, watch out when hiking, get yourself some mosquito spray.
Leptosporosis - the rivers are warm enough here to breed diseases.
Rat Lung Disease - Coming from snails going over lettuce especially. Wash your fresh vegetables.
Coral - It's way more complicated than a plant or an animal, and if it breaks off into your skin it could keep on growing. (And if you're going snorkeling, use an organic sunscreen so the coral isn't harmed)