What type of marine toilet unit is designed to treat sewage on boats over 65'?

The Type I marine toilet unit is specifically designed for use on larger vessels, such as those over 65 feet in length. These systems utilize a combination of treatment methods to treat and discharge sewage effluent directly into the water. They are engineered to meet Coast Guard regulations, ensuring that the treated effluent is of a quality that is safe for discharge in navigable waters. This is particularly crucial for larger boats that are often used for extended trips and may stay on the water for longer periods, making effective waste management essential for environmental protection.

In contrast, Type II units are designed for smaller vessels and are less effective in treating sewage than Type I units. Type III units, often referred to as holding tanks, do not treat sewage but simply hold it until it can be disposed of properly. Portable toilets serve a different purpose entirely and are typically used for recreational boats or smaller crafts, focusing on convenience rather than long-term sewage treatment. Thus, for boats over 65 feet, the Type I unit is the appropriate choice because of its advanced treatment capabilities.