I was looking through some old racing pictures and i see that most of the exhaust had water shooting out them but now race boats exhaust don't seam to have the water coming out them. Why is that?

Also i noticed towards the end of the 80's they started having the exhaust come out the side vs the rear any thoughts on why?

thanks for your input

Out the side was easy for Staggered engines. Right off the heads and straight out the side with a very smooth flowing angle and short rought. Water exiting out a seperate exit allowed for less back pressure, more noise, less chance for inversion with radical cam's and stronger closed end tail pipes.

Also considerably lighter to loose two long large jacketed pipes full of water and dump out the side.

was the water cooling the exhaust or the engines?

both....