My other thought was a portable power wash down...
I like this option the least but it seems like it would work?http://www.ebay.com/itm/PORTABLE-WASHDO
I am not that concerned about how long it takes to empty out 150+ gallons (some is always left - right) because the only times I will really use this is on long trips. (Motoring for 3-6 hours.)
However - she sits in saltware about 11.5 months out of the year and it would be good if the boat 'floated' about 2 inches higher than she usually sits with her ballast full. With the rudders raised and pointed towards the sky the tips of the rudder are submerged about 1" inch. means there is always growth on them. (Makes the Queen unhappy.)
I leave for the FL Marquesas Island's in 2.5 weeks. YEAH.