Yacht exteriors are quoted by length, so almost every buyer assumes the comparison will be settled on price per metre. In practice the quote is decided by a shorter list of questions: what is actually on the hull, where the work will happen, what services exist there, and what happens to the water afterwards. Those four answers rule machines in and out faster than any specification sheet. The questions below are the ones worth putting to a supplier, and to your own operations team, before you compare options.
1. What is on the surface, and where did it come from?
"Dirty" covers several different problems on a boat. Road and industrial film on the topsides; exhaust staining around the transom and near the stack; waterline tide marks and calcium deposits; anti-fouling residue and slime below the waterline; grease at the propeller shaft and cutless bearing; salt crust in the rubrail channels, hawse pipes and deck hardware. Each one behaves differently. Cold high-pressure water lifts loose marine growth and general film quickly and does little to baked-on exhaust staining or oil at the running gear. Where the deposit is oily or tar-bound, steam degreasing equipment is the method worth testing, because the heat softens the deposit so the pressure only has to move it rather than abrade it.
Ask the yard or the crew to list the deposits by zone — hull topsides, waterline, transom and running gear, deck, superstructure — before any supplier is approached. A supplier who knows what they are being asked to remove will tell you which mode and which nozzle to use; a supplier who does not will quote a machine and wish you luck.
2. Gelcoat, paint, foil or wood — what must survive the process?
This is the question that ends trials. Anything with a coating, an adhesive joint or a seal has a limit, and that limit is set by the boatbuilder, not by the cleaning contractor. Ask for the yard's written guidance on water temperature and nozzle pressure before anything is connected. Then check the specific items on your fleet: antifouling layers and whether they are intended to be abraded at all; anodes and their fixings; skin fittings and seacock housings; through-hull sensors, transducers and sonar domes; rubrails and their adhesive bedding; teak and its caulking; decorative striping, vinyl graphics and metallic paint; carbon spars and their finish; windows and their gaskets; and any warranty condition tied to pressure washing.
Two rules come out of that list. Never direct a jet at a seal, an adhesive edge, a skin fitting or a sensor face; and never test on the transom or the topsides where a mistake shows. Choose an out-of-sight area low on the hull, keep the first pass short, and photograph it before and after. A machine with switchable dry and wet steam lets you test the mildest practical setting first and work upwards, which is exactly what a coating test needs; the dry and wet steam cleaner approach means the same machine can put heat into a deposit on one pass and rinse with more water on the next, rather than forcing one compromise for the whole job.
3. Where will the work actually happen, and what can you get to?
Marine work happens in four layouts, and each one points at a different machine class. On a hardstand or in a haul-up shed, the boat is stationary, the crew can work all night, and power and drainage may exist — a fixed unit makes sense. Afloat alongside a pontoon, there is usually no power and no drainage, and every cable and hose has to cross a finger pier — a self-contained mobile unit is the only practical answer. On a trailer at a yard forecourt, access is good but the ground is uneven and the run-off goes nowhere controlled. In a mobile service model, the crew travels between marinas and cannot rely on any site at all.
Walk the location with the supplier's dimensions in hand. A fixed steam cleaning machine such as the PowerDe HW02 occupies roughly 1,200 × 800 × 1,200 mm including handles, runs on 220 V, and takes tap water through a 4-point internal-tooth fitting — so the questions are whether there is a socket on a circuit that will carry a 6 kW heater, whether the machine can be wheeled to the working position without being lifted over a step, and how far the hose must reach from where it can legally stand. Where those services are missing, the driving-style units in the Cleaning Equipment Series are built to move under their own battery power through tight access, which is what a pontoon or a crowded forecourt demands.
4. What happens to the run-off?
Ask this question early, because in most marine locations it constrains the method more than the machine does. Wash water coming off a hull carries antifouling biocide, copper and booster particles, oil from the running gear, and sediment. In the water, that discharge is normally prohibited outright. On land it usually requires containment and disposal through a waste route the yard already operates.
Put it in writing before comparing equipment: which areas are permitted to discharge, which require capture, who owns the interceptor or the bund, and what the crew must lay down to contain the run-off. A low-water process is not an environmental gesture; on a pontoon where no capture exists it is often the only compliant option, and it decides whether you are comparing a high-volume wash with a steam or hot-water unit at all.
5. What are the duty cycle and the refill cycle?
Boat cleaning is a long, low-interruption job, and it exposes two machine limits that a short vehicle wash never reaches. The first is water. The HW02 carries an 80 L tank, so on a large hull the crew refills repeatedly; ask how long a refill takes at the actual fill point, not in a showroom. The second is heat. With 6 kW of heating power, 160° steam temperature and 0.8 MPa vapour pressure, the machine is built for a duty cycle with a hot-water demand running for hours — so confirm with the supplier what the recovery behaviour is when the tank is refilled with cold mains water mid-job, and how long the machine takes to return to temperature before the crew starts cutting corners.
On a mobile unit, runtime replaces tank capacity as the constraint. Ask for the working runtime per charge at the mode you will actually use, the recharge time, and whether a spare battery or a shore connection is part of the configuration. A crew that cannot finish a 15 m hull on one charge has bought a machine that needs two crews, not one.
6. Who inspects the result, and against what?
A cleaning contract on boats is argued over detail, not over the hull as a whole. Agree the standard in observable terms before the first job: no tide line along the waterline; no dark streaking across the transom; no slime or growth in the rubrail channels, the hawse pipes or around the anodes; no visible oil at the propeller and shaft; deck, superstructure and windows clear and unstreaked; and the surface dry enough to move the boat or cover it afterwards. Name who signs it off — the yard manager, the skipper, or the owner's representative — and how a fail is put right without a second mobilisation.
Put the acceptance criteria in the comparison sheet. Two suppliers quoting the same boat against different acceptance standards are not offering you the same service, however close their prices look.
7. What is the risk profile, and does the machine address it?
Marine sites are wet, salty and short of fixed sockets, which changes what you should ask for in a machine rather than what you hope for. The HW02 listing covers leakage, short-circuit, high-temperature, high-voltage and water-shortage protection; ask the supplier how each protection behaves in practice and what the crew is expected to do when one trips — because a protection that gets reset repeatedly on a pontoon is a protection that is about to hide a fault.
The operator risks are just as concrete: steam at that temperature scalds bare skin almost instantly, and a working deck becomes simultaneously wet and slippery during the job. Ask what personal protective equipment the supplier specifies, and how the crew handles a tank refill on a moving pontoon. Then check the practical handling points — wheel size against the surface it must roll over, hose length against the distance it must cover, and how the machine is lifted on and off a trailer.
8. What does the trial have to cover?
Before you compare offers, insist on one trial, on your worst boat, at the location where you actually work. Choose a vessel with a real waterline deposit, exhaust staining on the transom and oil at the running gear — not the easiest hull in the fleet. Run the coating test on an inconspicuous area, then work the zones in the order you would on a real job, and record three things: minutes per zone, how many passes the worst deposit needed, and how far the crew had to move the machine to do it.
Those three columns settle most comparisons on their own. Time per zone tells you the labour cost, pass count tells you whether the method or the machine is the limit, and repositioning tells you whether a fixed unit or a battery-powered mobile unit suits your layout.
9. What is the cost per hull, not per machine?
Compare options on landed cost per hull: machine price and depreciation, crew hours at your rate, water consumption, energy, consumables and nozzle or hose wear, plus the cost of containment and disposal for the run-off. Add the cost of what the alternative method charges you elsewhere — a pressure-wash that leaves a bay standing in water, or a wash that cannot run at all on a pontoon and pushes the job to a haul-up with its own mobilisation charge.
A trial that records time and repositioning gives you most of that arithmetic already. A supplier who will not discuss it, or who answers with a brochure, is telling you something about the support you will get after delivery.
10. What back-and-forth does the buyer expect after delivery?
Ask what happens in the first months of use. Who answers when the machine will not hold steam temperature through a long job; which nozzles and extension wands are available for working at height along a superstructure; how quickly a worn hose or a failed element arrives; and whether the supplier will adjust the configuration after seeing your results. If the fleet spans several sizes and the berths vary, customized cleaning equipment is worth asking about rather than picking the nearest catalogue unit. Shenzhen PowerDe Automation Precision Equipment publishes the parameter sheet for each model in its cleaning equipment range; send the deposit list by zone, the site layout and your trial timings to the contact page and ask for a configuration built around those numbers rather than a price list.
Putting the questions to work
Take the ten questions into the comparison as a single sheet, ask every supplier the same ones, and record the answers side by side. Half of them will rule machines out before you reach price: the coating limits narrow the method, the site services narrow the machine class, and the run-off rules narrow what is legal to do at all. The remaining options can then be compared on the figures from your own trial — time per zone, passes per deposit, refills and repositioning per hull — which is a basis no supplier claim can argue with.
