Arced boat battery - performance issue?

Left our Tritoon in the water for a few weeks which I don't normally do. Forgot to turn off the master power and batteries were dead when I went to take it out of the water. Was in a rush and went to jump it off and accidently got positive and negative reversed when jumping it off. Engine had no power so I checked the main 60a fuse and that was blown. Replaced that and engine fired right up. Also blew my amp fuses for the stereo system. Checked all other fuses that I am aware of and didn't find any others blown. All gauges and other electronics seemed fine.

I wanted to run it wide open to make sure all was normal but I noticed a slight decrease in top end speed. Probably about 10-15%. RPMs were normal (6k by myself). Not sure if it was my ears or just me thinking it but engine sounded a little off as well. Felt sluggish. Checked prop and it looked fine. Prop was also submerged during that time sitting in water.

Boat also looks pretty damn dirty for just sitting in the water for a few weeks. I always take it out and have read that the dirty pontoons can affect performance as well. Seems pretty quick though for that to have any real effect.

Wanted to see if anyone had any thoughts.