HELP! What is this part? 97 challenger 787 engine

[Bartoncraft]

I have looked in all the manuals remotely related to my boat and I cannot find anything that tells me what the circled part in the pic is or what it does. Can anyone tell me what the circled part is? Part number? TIA

 

[etemplet]

Thermostat.

Seadoo parts ---->> Seadoo Parts House

 

[tobytd]

Temp sensor…over heat switch
278000194

 

[etemplet]

Temp sensor…over heat switch
278000194

Yea that's what I meant. LOL I wasn't giving him the number... just leading the way.