Yes. I had exactly the same problem. I went to Desty Marine at Hamble Point and they fitted a drain pump, new shower head/tap, in the basin and ran an outlet from the existing sump to a tee from the sink. Excellent job but not cheap. The only current snag is that the main pressure water supply is not quite enough for a good spray but we have used the system effectively. There is nowhere to hand the shower head so it is a manual excercise.
Colin Richards
Lucky Break