Must have? - no. Worth a couple hundred?, for peace of mind - probably. If a fire were to happen, most definately. Ironically enough, the Coast Guard will not even count such a system towards the minimum count of extinguishers required on board unless there's an external indicator showing the system is charged. Considering that handheld extinguishers need only 'wear' the mounting bracket, and show a needle in the green, the CG requirements makes no sense to me. Flying missles, ok. Automatic Halon-like systems?, no good without fancy bells and whistles.
There's several reasons why I'm considering installing one. First, if an engine area fire were to occur on my boat there's no way to fight it without lifting the sundeck pad, and as a result feed the fire with more oxygen. Also due to tight confines, there's no guarantee that even if I did lift the lid, I'd be able to get a good angle on the base of the fire. These are both non-issues with Halon-like systems. Another benefit of Halon-like systems, unlike the hand held extinguishers is no clean up. After the fire's put out by the Halon-like system, if you can find and correct the source of the fire, you could be on your way once again, this is not necessarily so with the powder/foam types. Worthy of mention is the automatic nature of the Halon-like systems, in some cases the first indication of a fire may be the alarms indicating that he system has deployed and extinguished it - compare this to smoke, grabbing for the extinguisher, remembering to pull the tab, lifting the lid, etc., etc.
The cost and install does not look too bad. From what I'm seeing, it looks like about $200 and maybe a three hour job.
