What are strainers in reference to boating safety?

Strainers in boating safety refer to obstacles in water bodies, such as fallen trees, branches, or debris, that can trap a boat or kayaker, posing significant risks. These objects allow water to flow through but can create dangerous situations by blocking the vessel's passage, potentially causing capsizing or entrapment. Boaters are advised to be vigilant and avoid areas where strainers are present to ensure safety on the water.