Pre-Season Yacht Sanitization
Prepare the yacht before the first guest arrives.
For captains, yacht managers and chief engineers bringing a yacht back to life after winter lay-up. We inspect and treat the air conditioning, fan coils, water tanks and distribution, and galley extraction in one planned programme, with sampling where appropriate and a technical report at the end. Prepare the yacht before the first guest arrives.
yacht experience
What often appears when a yacht comes out of lay-up
After months with systems switched off, these are the things crews most often notice in the first days back on board.
Why systems left idle need attention before restart
During winter lay-up the air conditioning is off, fan coils sit with damp condensate pans, and air in closed cabins barely moves. Dust settles on filters and coils, and humidity can allow mould and bacteria to grow on wet surfaces.
Water behaves in a similar way. In tanks and pipes that are not used, water stagnates, meaning it stands still, loses any residual disinfectant and warms or cools with the weather. That is when biofilm, a slimy layer of bacteria that sticks to the inside of pipes and tanks, can develop and later release bacteria into the flow.
When the systems are restarted, all of this is pushed into the cabins and to the taps and showers, just as the crew return and the first guests are expected. Pre-season sanitization deals with it before, not after, the yacht goes back into use.
Systems switched off for weeks or months.
Water stands in tanks and pipes; condensate stays in pans.
Dust, humidity and biofilm develop on idle surfaces.
AC and pumps push air and water through the system.
Crew notice odours, dust or changes in the water.
Systems should be clean and documented before this point.
Typical warning signs at recommissioning
Most of these appear within the first days of restarting the yacht. They do not confirm a problem, but they indicate what should be inspected.
Stale or musty air
A smell from the vents that fades slowly, or returns every time the AC starts.
Dirty fan coil filters and coils
Grey dust or dark deposits on filters, coils and condensate pans.
Water odour or discolouration
Earthy, sulphur-like or metallic smells, or cloudy water at first use.
Showers unused for months
Outlets in guest cabins that have not run since the end of last season.
Mould on surfaces
Spots on headlinings, lockers, bathroom seals or behind furniture.
Old grease in the galley
Filters and hood left with residue from last season, now releasing smell.
Not sure what your systems actually need?
Tell us the yacht, what the crew has noticed and where she is now: a technician calls you back within 24 hours and plans the survey around your programme.
What a pre-season programme can include
Not every yacht needs every item. After the survey we propose a programme based on what was found, the yacht's history and the season ahead. Each item links to the full service description.
Grouping the work into one planned intervention means one survey, one period of disruption for the crew and one consolidated report.
- HVAC inspection: air handling units, ducts and grilles, see HVAC and air duct cleaning
- Fan coil cleaning: filters, coils and condensate pans, see fan coil deep cleaning
- Water tank assessment and, where needed, fresh water tank sanitization
- Sanitization of the water distribution to taps and showers, see water system sanitization
- Legionella sampling where appropriate, through Legionella testing with an accredited laboratory
- Galley extraction inspection and galley hood cleaning if required
- Interior sanitization where required, see interior sanitization
- A consolidated technical report for the yacht's records
What we check at the pre-season survey
The survey is done with the captain or chief engineer, ideally before the crew move fully back on board. We need to know how long the yacht was laid up, which systems were drained or left full, and what work was done in the yard.
We then look at each system in turn and photograph what we find, so the proposal is based on the real condition of the yacht rather than a standard list.
- Air handling units, accessible ducts and supply grilles
- A representative sample of fan coils: filters, coils, pans and drains
- Fresh water tanks through inspection hatches, where accessible
- Water distribution: little-used outlets, showers, hot water calorifier
- Galley hood, filters and first section of extraction
- Signs of humidity and mould in cabins, lockers and crew areas
- Lay-up history, drained systems and yard work carried out
How the pre-season intervention is carried out
The sequence matters: air and water systems are cleaned before interiors, so surfaces are not contaminated again once they have been treated.
Planning with the crew
We agree the programme, the order of work and which areas must be free, around the yacht's recommissioning schedule and crew arrival.
Protection
Floors, furniture and delicate finishes are covered and masked in every area where we open equipment or ducts.
Air systems
Fan coils and accessible ducts are cleaned mechanically, with brushing and vacuum extraction, then sanitized. Closed spaces can be treated with ozone using the AM-20 mobile generator while empty.
Water systems
Tanks and distribution lines are treated with high-concentration ozonated water from our AWM-20 or MWM-20 units to break down biofilm, and outlets are flushed. Residual levels are measured with digital meters afterwards.
Galley and interiors
Galley extraction and interior surfaces are cleaned and sanitized as agreed in the programme, once the systems that feed them are clean.
Sampling and report
Where appropriate, water samples are taken for analysis by an accredited laboratory. You receive a technical report with photos, readings and recommendations.
A fan coil after lay-up: before and after
Illustrative images of a cabin fan coil after several months of inactivity, and after cleaning. They are not photographs of a specific job.
Illustrative visual showing the type of condition we find and the result we work towards. Photos of real AirBio Marine jobs are shown in the gallery below and in every client report.
Pre-season work on board
Photos from real AirBio Marine jobs: the MWM-20 water unit on a protected aft deck, a residual reading taken after treatment and a cabin fan coil opened for inspection.
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What you receive
Consolidated technical report
One document covering every system treated, the methods and products used and the areas not reached.
Photos by system
Before and after photos of fan coils, ducts, tanks and galley, organised by area.
Readings where taken
Residual measurements taken with digital meters after water treatment.
Laboratory certificates
Where sampling is carried out, results from an accredited laboratory, attached to the report.
Recommendations for the season
What to monitor, flush or clean during the season, and what to plan for the next lay-up.
Maintenance plan option
A proposal for scheduled hygiene work through the year, if you want one.
One report for the yacht's technical history
Every job closes with a written report: what was inspected, what was found, what was treated, photos before and after, readings where taken and recommendations for the next check. Useful for the captain, the management company, the next survey and the next season.
Who this service is for
Gets the yacht's air and water systems checked and treated before crew and guests arrive, with one report covering everything.
Coordinates system isolation and restart with us, and receives findings on fan coils, tanks, calorifier and extraction to plan the season.
Can include pre-season hygiene in the recommissioning budget and keep a documented record for the owner and management company.
Starts the charter season with systems documented as cleaned and sanitized, reducing the risk of early complaints about smells or water.
Where we carry out pre-season sanitization
We work in marinas and yards along the Italian Riviera and Tuscany, and in other Mediterranean ports on request.
Monaco
Spain
and beyond
Wherever you are in the Mediterranean, we can be there.
Book the survey before your next movement
We work in the main Mediterranean marinas and refit yards, with documented results and lab analysis where required.
Pre-season sanitization: frequently asked questions
When should pre-season yacht sanitization be done?
Ideally after yard work is finished and before the crew move fully back on board and the first guests arrive. If it is done before refit work ends, dust from the yard can contaminate the systems again. We usually agree the timing with the captain or yacht manager based on the recommissioning schedule, so the systems can be restarted clean.
Do we need every service in the programme?
No. The programme is built from the survey. A yacht whose water system was drained and treated before lay-up may need less water work than one left full for months. A yacht with recent HVAC cleaning may only need fan coils checked. We propose what the findings justify and explain why each item is included.
Is Legionella testing always part of pre-season work?
Not always. Sampling is recommended where water has stagnated, where hot water systems were off for long periods, or where management-company or charter requirements ask for it. Testing shows the situation at the moment of sampling; it does not sanitize the system and one negative result does not guarantee future safety. It works best alongside sanitization and regular flushing.
Why clean the air conditioning before the interiors?
Air conditioning recirculates what is inside the fan coils and ducts. If the interiors are cleaned first and the AC is restarted afterwards, dust and particles from the system can settle on freshly cleaned surfaces. Treating the air and water systems first, and interiors last, keeps the results of each step.
Can the crew stay on board during the work?
Usually yes, with some areas temporarily closed. Ozone treatment requires the treated space to be empty and ventilated afterwards, and water outlets are out of use while the system is treated and flushed. We plan the order of work with the captain so the crew know which areas are available at each stage.
What do we receive at the end?
A technical report with photos of each system, areas treated, products and methods used, residual readings where taken, laboratory certificates where samples were analysed, and recommendations for the season. Many yacht managers keep it in the yacht's technical file as a record of recommissioning.
Related services
Yacht Hygiene After Winter Lay-Up
What months of still water and closed cabins can leave behind.
Yacht Fan Coil Deep Cleaning
A new filter does not clean the coil, tray and drain behind it.
Yacht Fresh-Water System Sanitization
From tank to shower head: the whole fresh-water network, treated as one system.
Legionella Testing for Yachts
A structured sampling plan, accredited lab analysis and results explained clearly.
Tell us about the yacht
Yacht length, marina, systems and what you have noticed on board. A technician reads the message and calls you back to plan the survey.
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Where we work
Italian Riviera and Tuscany marinas and yards — Viareggio, La Spezia, Portofino, Genoa, Sanremo, Livorno, Argentario — and other Mediterranean ports on request.
Documented work
Every job ends with a technical report and photos for the yacht's records.
Not sure where the problem starts?
Let the technical team assess it onboard.
In marina, at the yard or during lay-up. We tell you what needs treating — and what doesn’t.
+39 0584 433 198Expertise.
Peace of mind.