Looking for the right word to describe a chainsaw revving underwater in a menacing way [closed]

I am searching for the perfect word to describe a chainsaw sound. The chainsaw is revving under water (think Friday the 13th film). The actual sound is a boat motor but the receptor of said sound hears chainsaw motor thus invoking fear or dread.

So I googled and was directed to this site where someone else was also trying to describe a chainsaw sound, albeit not submerged in water. Some decent suggestions were offered but not quite right or effective. The words I am searching for must be stronger than buzz but connote a similiar esthetic. The vibe needs to be fearful or menacing...cold dread. The sound also doubles as an innocous boat motor so it ideally would play both ways, danger or fun.

I wanted to contribute to the original question found on here for feedback but I am new so I don't have points. Therefore, I will post the question again along with words I have come up with thus far. I have used the theasauras and dictionary for several of those listed below. The context the word will be used in is as follows:

Under the water, where the beautiful silence lived, I felt safe for a moment. I could hear music faintly in the distance from the shore and was just placing the song when the silence shattered like glass and ...?.?.....Chainsaw. Loud and abrasive. Slicing through my underwater peace. My insides iced over. Cold dread swept over me.....

All suggestions and/or feedback encouraged. Think menacing chainsaw motor underwater screaming imminent danger.
Previous suggestions were rattle, brattle, roaring...
I am coming up with...growl, rumble, revving zoom, thunder rattling, guttural wizzing, bellowing zip, razor zip...steel chatter, aluminum shuddering...can't quite nail it...ideas?

English has been around for nigh on 1,500 years and in that time most all phenomena have been described. Strangely, native speakers have omitted the particular noise made by a chainsaw underwater. This is an omission for which I can only apologise.

To keep in tune with the underwater content and the general feeling of uneasiness occasioned by an underwater chainsaw, I suggest

"... and from beneath the surface of the water came the gurgling rasp of a chainsaw.

As an aside, could you please explain how the internal combustion engine of said chainsaw manages to keep running underwater, what is the source of the air needed?

The realistic alternative might be "They perceived the absolute silence of a chainsaw that cannot run underwater", although I do realise that this may introduce an element of bathos.