From BoatUS website ...... they do mention one propane fire but that is only to be expected when you use a non-approved portable unit on a boat.
Causes of Fires Started Aboard
Click on the links below for more information:
1) AC and DC wiring/appliance - 55%
2) Engine/Transmission Overheat - 24%
3) Fuel Leak - 8%
4) Miscellaneous - 7%
5) Unknown - 5%
6) Stove - 1%
Stove fires appear to be less common (1%) than in the past, probably due to fewer alcohol stoves being installed on new boats. Still, alcohol can be a dangerous fuel; though it canít explode, an alcohol flame is hard to see. One fire was started when a member tried to light the stove and gave up because he couldnít see the flame. Unfortunately, he had succeeded, but didnít realize it until he got a call from the fire department. Only one fire was started by propane; a portable stove fell off a counter and ignited a cushion.
Thanks for digging that up.
But come to think of it: it is indeed quite unlikely that propane would start a fire
Do they have by chance a column where they show the causes for explosions
Clearly, there are quite a few boats that explode because of problems with their propane systems (the second hit of the google keyword search shows one last month) so some of them must be insured by BoatUS.