Engine Temps with warmer water

[CurrentSea]

Boat normally runs at 165 to 170, but last night it was running 170 to 175 and sometimes a little higher. I thought it was due to alot of seaweed in the water, but reverse was not lowering it much. I am FWC. I did notice water temp of the water is running around 84 degrees, which is exceptionally warm for us.

So the question, does water temp of bay affect the water temp of the engine and if so, to what degree? If you boat in 70 degree water and engine runs 165, then does 100 degree water run it at 195!!!!???

Thanks