Hilo nearly got hit with a major lava flow in the 1840’s and has been walloped twice by tsunamis. We went to the Pacific Tsunami Museum there, which is often staffed by people who survived them.
Hawaii now has buoys in the Pacific which can provide multi-hour early warnings. Plus they have a sophisticated evacuation system and building and flood plain codes. Of the two worst tsunamis, one came from Alaska in 1946, the other from Chile in 1960. They are caused by earthquakes in the ocean, and can sometimes generate as many as ten walls of water.
Best advice: If you are in a tidal area and feel an earthquake, evacuate immediately.
Between the Goddess Pele sending down lava and the ever-present possibility of tsunamis, perhaps it’s understandable why some might wish to partake of cannabis.