Sick Yacht Syndrome

May 21, 2009 / AIR, Water

Sick Yacht Syndrome


Norwalk Virus, bilge odors, flesh eating bacteria, mold, yeast, holding tank odors, VOC’s, stale air, diesel bacteria – all are

indoor air problems on a yacht. The question is why are indoor air problems magnified on a yacht and how can we control

them? Indoor air problems or sick building syndrome is a widely recognized, universal health problem. What is new and

gaining attention is Sick Yacht Syndrome. The indoor air problems of a home or office building are miniscule compared to

the indoor air problems of a yacht. The problems with yachts or any vessel are numerous. By nature, just the fact that you

have a tightly sealed vessel in a dark, damp atmosphere with wide temperature differentials, and a wide array of mold, bac-

teria, odors and microbial food sources available leads to potential major indoor air health problems.

Yachts are notorious for stale air. You notice it as

but may remind the next person of a funeral home! The

Stale Air.

soon as you step onboard. You have a trademark odor.

best scent engineering is non-scent or the absence of all

Some try to mask odors with another odor. Companies

odors. Routinely, hotels have to change drapes and bed-

actually specialize in “scent engineering”, tying certain

spreads not due to wear, but rather the absorption of odors.

scents with feelings or moods. The problem with this con-

This problem is amplified on a yacht due to the wide variety

cept of olfactory persuasion is we all process odors differ-

of odors.Yachts are built tight. Space and weight are design

ently. Roses may smell good to you and make you smile,



Sick Yacht Syndrome

Typical petri dish

air sample


Healthy Yacht Syndrome

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Therefore heating, ventilation and air conditioning (HVAC)

Wastewater Related Diseases and Viruses from Inhalation*

equipment is kept to a minimum. Make-up air or fresh out-

• Tuberculosis

• Bacteria Dysentery

side air is limited or non-existent.

• Histoplasmosis

• Common Cold

Make-up air should represent 25% of a yacht’s airflow.

• Coxsackie A&B

• Echovirus

Designers prefer to recycle air as it is usually warmer or

• Adenovirus

• Rotavirus

cooler than outside air, so less energy is required to heat or

cool the air. The problem is you are continuously turning

*Water Pollution Control Federation

over the same air. This is especially true in the lower state-

rooms. Assuming no one opens a port hole and each state-

are gaining worldwide attention. Multimillion dollar


room has its own air handler (heating/cooling unit) and two

homes are being razed due to mold contamination.

people are in a stateroom with the door closed, there is no

Insurance companies are excluding mold damage from their

fresh air circulating, just recycled air. This is true for the

coverage. Mold spores are everywhere. All they need to

entire lower stateroom area. The only way to get fresh air is

grow is still air, moisture and a food source. Yachts provide

down the stairway via Brownian motion or a very slow

a perfect atmosphere for growing mold. Ideal food sources

molecular air transfer. Trying to get fresh air down a stair-

are leather, paper, fabric and wood. This combined with

way into closed staterooms is like trying to blow air into a

stagnate air and dampness produces a perfect mold farm.

bottle. The old air has no place to go so you end up with a

static air situation. With all the airborne bacteria, molds,

yeasts and VOC’s, this build up can cause very serious

problems. Most bacteria are harmless, but when you have a

build up of billions, you drastically increase your chances of

exposure to a bad one.

. A yacht can carry anywhere from a few hun-

Diesel Fuel

dred to tens of thousands of gallons of diesel fuel. The fuel,

Healthy Yacht Air Sample

Sick Yacht Air Sample

of course, is confined to the fuel tank. Most yachts have a

diesel fuel odor. Some are subtle, some are stronger.

or volatile organic compounds are a common indoor


Assuming there are no leaks or spills, you will still get diesel

air problem as they are everywhere: cleaning compounds,

odors from the fuel tank vents that relieve air pressure

plastics, furniture, etc. All are found on a yacht. However, a

caused by fuel displacement of air and temperature varia-

yacht will have much higher levels of VOC’s then a home

tions. Fuel vents vent outside the boat. However, some

due to all the glues, sealants, oils and fuel, and a fiberglass

diesel odors always seem to find their way inside the yacht,

vessel will be continuously off gassing VOC’s.

plus the engine room usually has lots of small leaks and

venting. Why is this important to the yacht owner’s indoor

is a unique strain of bacteria that can live in a very


air problems? Aside from diesel fuel odor being unpleasant,

cold atmosphere and is often found in sink and shower

diesel fuel is a microbial breeding ground and food source.

drains and ice makers. When food poisoning breaks out in

Diesel fuel has the ability to harbor and grow 30 types of

a restaurant and nearly everyone gets sick, it is usually

bacteria, 12 yeasts and over 80 fungi species. When fuel

from the ice machine lysteria bacteria. Most patrons are

odors are present, these odors actually represent minute

served ice and water or ice in a drink. Lysteria loves yachts

aspirated fuel particles that could easily be carrying some of

– lots of ice machines, lots of drains and shower sumps to

the bacteria, yeast or fungi known to grow in diesel fuel.

grow in. Drains, shower sumps and heads also add to the

yacht odor and overall bacteria problems.

. All yachts have bilges, and with them come

Bilge odors

odors, oil, fresh water from air conditioner condensers, and

represents a very serious problem to the

Norwalk Virus

soapy wash water. All are excellent breeding grounds for

cruise and yacht industry. Thousands have been infected

bacteria. Oil, like diesel fuel, contains bacteria, yeast and

and many cruises cut short. Why is Norwalk so prevalent on

fungi. Soap and detergents contain phosphates, a fertilizer

a ship? Norwalk is most likely transferred by confined envi-

for our lawns and gardens and also fertilizes microbial

ronment and surface to hand contact. It is very difficult to

growth. As with diesel odors, bilge odors aspirate minute

contain. Disinfect surfaces or wash your hands frequently.

particles of bilge water loaded with microbial and food

sources for the microbials.

There is a strain of staph that is frequently

Staph Bacteria.

and accurately reported by the media as flesh-eating bacte-

. Yes, sewage stored in a yacht holding

ria. The wounds are black, and it literally digs a hole into

Holding tank odors

tank can run from 50 gallons to over 5,000 gallons. Again,

your flesh. The full name is streptococcal bacteria and it

these tanks are vented outside of the hull, and are a huge

does eat flesh. There have been an unusual number of

source of bacteria, viruses, methane, and hydrogen sulfide

cases on yachts. Why yachts again? They are ideal breed-

gases, and of course, odors. These sewage gases, bacteria

ing grounds for microbials and the higher number you are

and odors always seem to find their way into the yacht,

exposed to the harder time your immune system has fight-

again providing microbials as well as food sources for the

ing them off and the higher the odds are you will be


bials themselves.

exposed to a dangerous microbial.

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• A positive ventilation, oxidation and circulation system.

This will kill microbials as above, plus provide full vessel air

circulation to prevent stale air pockets.

• An advanced oxidation holding tank ventilation system.

Advanced oxidation gases are circulated through the hold-

ing tank to oxidize sewer gases, viruses, bacteria and


Staph infected leg also known as Flesh Eating Bacteria

A finger infected with Flesh Eating Bacteria

All of the above lead to Sick Yacht Syndrome. All can be

Holding Tank Ventilation System

controlled. With the right program, your yacht can be as

•An advanced oxidation fuel filtration system. This will kill

fresh as the air at sea.

microbials in diesel fuel without the use of chemicals.

Healthy Yacht Hints

Engines will run cleaner and fuel microbials will be limited.

• Good housekeeping. Keep it clean and clutter-free to pro-

mote air circulation.

• A filtered advanced oxidation fresh air makeup system.

This will help prevent stale air and provide a positive pres-

sure atmosphere in the yacht.

• A continuous duty advanced oxidation HVAC air purifica-

tion system. This will kill airborne and surface bacteria,

viruses, mold, yeast and odors.

Advanced Oxidation Fuel Filtration System

HVAC Air Purification Unit

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• A continuous duty advanced oxidation ice machine and

sive gases are developed by targeting a high intensity UV

drain system to kill lysteria bacteria.

light on a precious metal target. Unlike ozone generators,

advanced oxidation systems use redundant safe oxidizers

Advanced oxidation is a new technology that uses friendly

and are widely used by all major food processors, the mili-

oxidizers to oxidize (kill) mold, viruses, bacteria, yeast,

tary, major cruise ships, homeland security, hospitals,

VOC’s and smoke into harmless CO2 and water. By friendly

assisted living facilities, hotel chains, etc.

oxidizers, we mean oxidizers that turn into safe oxygen and

Envision is owned by RGF and is the world’s first enviro-

hydrogen when the oxidation or kill occurs. Advanced oxida-

friendly mega yacht. Envision is equipped with over 50

tion or PHI cells create gases and ions such as hydro-per-

advanced oxidation PHI technologies and provides its

oxides, superoxide ions and ozonide ions. These aggres-

guests with a safe chemical and microbial-free atmosphere.

Envision, The World’s First Environmentally Friendly Megayacht

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