I have used them on my wet exhaust. Summit has a great selection.
https://www.summitracing.com/search/...licon+couplers

wow

Here's some pics of how I used the silicone "couplers".

So this has a little more "flex" than traditional Marine wet SAE J2006 "rubber" coupler?

ive been burning through my blue trident marine silicone tubes (rated 350f), I just purchased this and will report back once its arrived and installed, supposedly rated for 428f
my starboard side seems to be keeping intact just fine, but port must have uneven flow of water in the risers causing a certain spot to be burnt out

Yes, a lot more.
I do run them wet. Water enters at the connection.

I too am running wet so THANKS!

I used silicone hoses for 4" exhaust tips and a bit smaller ones downward to somehow connect silent choice diverters with 6" riser extension blocks. I had to mount the riser to the extension block last, and used an engine crane (!) to get all pieces to bend to the right position at once so I could bolt it down. I could not have done it with rubber, just impossible.
No problems at least for one season.

My hoses were not for exaust specifically, but manufactured to withstand steam, air, water, high temps and oli/fuel mist.

PO of my boat had 4” silicone coolant hoses and they’ve worked for 10yr