Pressure washer for a start.
Algae on the outside doesn't affect it.
My Volvo drive looked like that every year after I pulled it out. I would just clean it.
Just so you know, there is no upper unit with oil in it...just a lower unit. All you would have to do is separate the lower unit to see what is happening. You should be doing this every two years anyway to replace the impeller.
I think you are mistaken. One of the three that was out before averages 2 points. McCormack played tonight. Not sure of the other player. USC is very good....and I hate to say that. Kansas is always overrated