I like the image very much and I think your use of the filter has been a success. I hope you tried it without the filter as well.
I do find the composition a little too cluttered by the masts of the foreground yachts - I think you wanted to show the strength and power of the ferry by comparison with the yachts here and I think I might have composed this from further to the right, keeping in the red boat in the left foreground but removing some of the masts from in front of the great side of the ferry, keeping just a few on the left for comparison. Of course I was not there so don't even know if this would have been possible! A