Jet ski won't start?

[Water-D]

I have a 1994 Kawasaki 750 XI jet ski. I haven’t used it for couple of years. I hooked up a new battery and press the start button when I was in my garage. At that time it wanted to start, but I didn’t crank it long enough to start, because I wanted to wait till I go to the lake to fully start it. I toe the jet ski to lake, put it in the water, tried to start it.. no sound. Nothing turns. My initial thought was starter relay went bad while I was toeing it (due to vibration) and replaced it. Still nothing. I **passed the relay and short the starter cable across, then start motor kicks in. If it is not the relay what is it preventing the start motor to kick in? Please any help would be much appreciated. Thank you.