So let's review.
You have an ingress of liquid, of unknown origin, and composition.
This liquid amounts to about 15 gallons in an unspecified period, and it is being captured in a floating vessel of a fixed volume and should be considered "cumulative"
The "as designed" facilities for removal of the liquid are not operational, understood, and there appears to be a lack of stated expertise in getting them running.
So, it would be safe to assume that without the availability of a large scale bucket and some form of scoop, this issue will persist for the foreseeable future? It might be time to hire a boat mechanic. Maybe before this liquid gets into something that you can't bail out.