Do yourself , and your passengers, a favor a get the spark arrestors , (or marine alternator itself)for the alternator. Favor is just a figure of speach.

You just haven’t gotten enough fuel vapor's in your bilge yet.

You have smoke detectors and etc in your house ?

Fyi: only one person loses in Russian roulette.

and yes I’ve seen , in person, probably five boats now engulfed in flames.

SB - All the alternators I see marine rated none of them are 100amp or more and I do not want a automotive unit in my boat for the obvious reasons. Can you recommend one so I can get it ordered and check this box?

I've been using these for almost 20 yrs.
https://www.dbelectrical.com/product...ch-140amp.html

I was just on their website too. going to order one up now.

Or take your marine Alt and find a local Alt and Starter repair/rebuild shop. There's one around my area that ive had them take a standard 80amp and build it to a 160 amp in the past...