Very very quiet. A volume increase is definitely required. I also think that waves on a shore being repetitive isn't really a great way to view the theme because it detracts from the music rather than inspiring it.
There are probably more listener friendly ways of making the waves on a shore interesting musically such as having lots of fade ins and outs or by just using waves as background noise for the ambiance.
Well what I mean is that when given a theme, sometimes taking it in a certain way limits your flexibility to a degree that makes the music worse overall.
For example, in my first music jam I did the theme was an endless maze and I tried to convey that by having the same 8 bar stanza repeat but adding new instruments every time as if you were gathering new items along the way.
While yes it technically fit the theme, it ultimately detracted from the whole piece because my decision forced me into a box that prevented more interesting ways to express the theme.
I think the reason I see the repetition in your piece being a hinderance is because it is the ONLY piece you have. If you had say a few more tracks then a song representing the repetition of waves wouldn't be as much of a detraction. But because you only have the 1 track, making it intentionally repetitive seems like a bit of a poor decision.
I don't mean this to be mean by the way! I just remember when I did almost the exact same thing and other people also told me very similar things of how I could have handled the theme better.
I hope this helps!
