Proper ventilation is important not only for good maintenance of your boat but also for the safety of the passengers. Without ventilation, your boat could suffer damage to its interior. Proper ventilation also ensures that toxic gases and fumes don't build up inside the boat.
Problems related to poor ventilation
When your boat is not properly ventilated, hot, humid air builds up within the interior. Because your boat is normally on the water, the humidity will be even more severe than under normal, properly ventilated conditions. This hot, moist air leads to a variety of issues with your boat's interior, including:
Ventilation can also affect you and your passengers. Some side effects of poor ventilation can include:
Some of these problems can be life threatening. The importance of proper ventilation, then, cannot be overemphasized.
Types of ventilation
You can ventilate your boat in several ways. Use more than one type of ventilation to be sure air can move both into and out of the boat. Additional vents also help dispel odors from areas such as the bilge and head. Ventilation systems can be passive (letting air pass naturally in and out) or active (using a fan to move the air).
An example of passive ventilation is a louvered vent or open hatch. Louvered vents let air in and out but don't allow rain into the boat. Opening the hatch is a simple way to bring fresh air into the boat, but this won't keep out the rain.
Active ventilation is achieved with fans, which can be powered in various ways, such as with batteries, solar power and electricity. When deciding on a ventilation system for your boat, bear in mind that using a combination of methods yields the best results.
How much ventilation is enough?
The amount of ventilation you need depends upon the size of your boat. The necessary square footage of ventilation can be determined by multiplying the boat's waterline by the beam length in feet. You also need more ventilation if you are out on the water in bad weather, simply because you won't be able to leave hatches open to help move fresh air through the boat.
The ventilation options with which your boat came equipped may or may not be sufficient. If you feel that your boat is uncomfortably hot or humid, or if you experience headaches or other symptoms while you are out on the water with the boat closed up, consult with a professional, or install additional ventilation on your own. In terms of comfort and safety, the additional money and/or work will be well worth it.