Great South Bay…huh.

Could be some seaweed or other debris got In There and it’s preventing the thermostat from fully closing

Sometimes a good ride at a higher rpm could help dislodge it. Or you may have to remove the thermostat housing and clean it out.

When was the last time you replaced the thermostat?

 

Can't speak specifically to your Alpha1, but on my 8.1s there are two sensors. One goes to the dashboard gauge, the other goes to the computer (alarms, etc). A stuck thermostat is a possibility, so is a bad gauge, or a bad sensor.

I keep one of these in my bag of tricks so I can check out temps in various parts of my engines...
https://www.homedepot.com/p/Milwauk...m/p/Milwaukee-Laser-Temperature-Gun-Infrared-10-1-Thermometer-2267-20/206260202

 

GSB means it could definitely be seaweed holding it open or it's just plain stuck open. I'd change the thermostat first. As they say KISS(keep it simple stupid) it's usually the easiest fix.

 

I ordered all the parts I might need for the thermostat and I’ll bring my temp gun at the next chance I get to go out. Will running it at 135ish do damage?

 

135' isn't all that far off, but keep in mind; the engine needs to get up to operating temp to help boil out any residual acids and moisture from the engine oil, plus it'll cut a bit into your fuel economy.

 

Common problem with a salt water open cooled system. Rust flakes from the block will get caught in the t-stat

 

135 is not ideal but it really will just make you run rich and burn more fuel. Long term answer is yes it will cause more wear over the life of the engine.