Rendering is nice, but it just doesn't look realistic, the composition is a bit boring too.
I don't know a lot about it, but I'm sure it would've helped if you studied references of speedboats, jetski's etc. before you did this.
Also creating thumbnails to find a composition that looks good is important.
It's an appropriate Christmas present and I bet you've already gave the lucky guy his caricature
Next time, think more about composition, there's no design to this picture.
Having a solid composition usually improves the picture about a billion times more than texturing background stuff.
Here's an easy trick: Make one thing in the picture really big, one mid-sized and one thing tiny.
That's a good emergency plan if you don't have a lot of time to fumble around with compositions.
In this example you could've made the head far far bigger, the boat a lot smaller and leave the body tiny as it is.
Right now the boat is midsized, the head is somewhat midsized and the body is small.
Just try to apply this tip for yourself with the lasso tool.
Resize everything and make the big things even bigger and the tiny things even smaller.
And then do it again, I'm 100 % sure that you will be too timid on the first try .