When cleaning boats with a crew on dry dock one must consider water usage and time to wash, as these will affect the variable costs of each unit cleaned. Additionally it will be important to average the number of boats of various sizes, which one expects to wash with the estimated time to wash each size. The amount of water anticipated in usage will be a factor also for the environmental filtering of the wash water.
Most high-pressure hot water units put our about 4.6 gallons per minute to 5 Gpm; a well trained boat washing crew could clean a 30 foot hull, by doing in quarter sections at a time, in about 8-10 minutes per quarter. This is if dirty, fairly bad. But you would not be spraying the whole time. The crew would rinse it good and brush and then rinse it again. With inline injection system one might find that the length of hose was 80-100 feet and that takes 1:00 to feed soap and 1:00 to rinse. If you did this 2 times per quarter then you need to add 8 minutes to the total job. However when feeding soap the pressure is dropped down and there would be a slight different in the amount of water used but not much because even though the pumps is not working as hard the volume of water only fluctuates a little, but still realize you feed 8 more minutes at the 4.6 GPM.
It maybe advisable to use a different unit to apply soap and thus saving the 8-minute feed time for soap, allow for additional dwell time of soap on the boat hull and reduce the time to clear the line for regular rinse water to move from the pump to the high-pressure spray nozzle. One could go with an airless sprayer system, Hudson industrial type spray or another cold-water pressure washer of 5 HP that put out 1.8 GPM, Honda has a nice little unit for this. However for the 4.6-5 GPM spray unit it is recommended to go with an industrial skid unit. I recommend a Hydrotek Hot Water Pressure Washer Machine for this use.
http://www.hydroteksystems.com/
So lets be safe and say that you will use 58 minutes to clean the 30-foot boat hull and of that you might be spraying about 30-40 minutes for dirty boats, with film and crud on them? Now then to average out your usage think of how many boats and which sizes you will be washing, this I do not know, as each Marina will be different, however one might assume those folks with larger boats would have the money to pay you to clean them more often, this is what we have found. Now then, a not so dirty boat 30-foot you should be looking at 20 minutes wash time total minus soap feed time for inline injection unless you have another unit to spray on the soap.
Below are articles I have written relating on this subject, which can assist anyone starting a boat cleaning business or expanding a current business. Think on this.
http://ezinearticles.com/?Rotary-Boat-Hull-Cleaning-Systems&id=69179
http://ezinearticles.com/?Boat-Hull-Cleaning-Equipment-Needed&id=36461
http://ezinearticles.com/?Boat-Hull-Cleaning-Procedures-for-Owners-and-Detailers&id=36464
http://ezinearticles.com/?Boat-Cleaning-Business-Bilge-Clean-up-Tips&id=25176
http://ezinearticles.com/?Meguiars-RV-and-Marine-Boat-Cleaners-and-Waxes-Test-Results&id=31238%20
http://ezinearticles.com/?Future-of-Robotic-Vessel-Hull-Cleaning&id=68832
http://ezinearticles.com/?AUV-Solar-Powered-to-Monitor-Lake-Ponchartrain&id=70284
http://ezinearticles.com/?Debates-in-Auto-Detailing&id=38845
http://ezinearticles.com/?Maximum-Efficiency-in-Auto-Detailing-Shops&id=38779
http://ezinearticles.com/?Robotic-Underwater-Boat-Hull-Cleaners-Have-Military-Applications&id=68845
http://ezinearticles.com/?Boat-Washing--Spring-is-Here,-Lets-Go-Boating&id=24206
http://ezinearticles.com/?Robotic-Boat-Cleaning-is-Here,-Soon-it-will-be-Affordable&id=25574
http://ezinearticles.com/?Water-Filtration-Choice-for-Mobile-Car-Washes-and-Detailing&id=41785
http://ezinearticles.com/?Water-Softener-Use-In-Mobile-Auto-Detailing&id=41562
http://ezinearticles.com/?Boat-Cleaning-Business-Case-Study-Entrepreneurship-&id=40939
http://ezinearticles.com/?Yacht-Winterization-Service-Business&id=39752
http://ezinearticles.com/?Boat-Winterization-Services-and-Charges,-Part-I&id=39755
http://ezinearticles.com/?Boat-Winterization-Services-and-Charges,-Part-II&id=39757
http://ezinearticles.com/?Boat-Detailing-Stainless-and-Chrome-Cleaning&id=25182
http://ezinearticles.com/?Boat-and-Yacht-Detailing-Teak-Reconditioning-and-Care,-Detailing-the-Deck&id=24536
http://ezinearticles.com/?Reclaim-Equipment-Detailing-Industry-and-NPDES,-EPA,-Storm-Water-Rules&id=38599
http://ezinearticles.com/?Reverse-Osmosis-and-Deionized-Water-Filtration&id=41789
http://ezinearticles.com/?UV-Light-Water-Filtration-Devices-for-Flood-Victims&id=66501
http://ezinearticles.com/?Cleaning-Canvas-Tops-on-Boats&id=27285
http://ezinearticles.com/?Dock-and-Deck-Cleaning-Business&id=36449
http://ezinearticles.com/?Environmental-Boat-Washing-and-Detailing&id=36467
http://ezinearticles.com/?Preventing-Boat-Propeller-Injuries&id=49712
http://ezinearticles.com/?Adding-Battery-Cleaning-Services-Secrets-from-the-Auto-Detailing-Industry&id=25306
http://ezinearticles.com/?Boat-Detailing-Diagnosing-Gel-Coat-Surfaces&id=25183
http://ezinearticles.com/?Cleaning-Sails&id=27847
http://ezinearticles.com/?Advice-for-Pressure-Washing-Companies-Cleaning-Marina-Docks&id=36454
http://ezinearticles.com/?Mobile-Detailing-and-Environmental-Laws&id=27844
http://ezinearticles.com/?Environmental-Compliance-Mobile-Auto-Detailing&id=36946
http://ezinearticles.com/?Boat-Detailing-Final-Process-in-the-Reconditioning--Applying-the-Protective-Sealant-on-Gel-Coat&id=25181
http://ezinearticles.com/?Dock-Cleaning-Procedures&id=36452
http://ezinearticles.com/?Hydrofoils-as-Strike-Vehicles-on-Water-Fast,-Safe,-Smart&id=25573
http://ezinearticles.com/?Marina-Dock-Cleaning-Equipment&id=36451
http://ezinearticles.com/?Tips-on-Marina-and-Dock-Sealing&id=36456
http://ezinearticles.com/?Water-Molecule-Alignment-for-Increased-Speed-In-the-Water&id=25572
http://ezinearticles.com/?Self-Cleaning-Counters-is-a-Smart-Way-to-Prevent-Diseases-in-QSRs&id=25196
http://ezinearticles.com/?Auto-Detailing-Choosing-the-Correct-Buffing-Pads-for-the-Job&id=25179
"Lance Winslow" - Online Think Tank forum board. If you have innovative thoughts and unique perspectives, come think with Lance; www.WorldThinkTank.net/wttbbs/