What should be used to mark spoil areas, traffic separation, or jetties?

Using a special purpose mark is the correct choice for marking spoil areas, traffic separation schemes, or jetties. Special purpose marks serve specific navigational needs that do not fit into the other categories of navigational aids. They help to indicate areas that require caution or are designated for specific activities, allowing mariners to understand the nature and purpose of such zones clearly.

In navigational contexts, spoil areas, traffic separation zones, and jetties often pose unique navigational considerations, making the distinct identification provided by special purpose marks crucial for safe navigation.

While lighted buoys can indicate positions at night or in poor visibility, their primary function is not specifically for spoil or separation areas. Daymarks, while useful for daytime visibility, also serve a broader purpose and may not convey the special characteristics of spoil areas effectively. Lateral marks are intended to indicate the sides of navigable channels, which does not apply to the unique context of spoil areas, traffic separation, or jetties. Therefore, a special purpose mark specifically meets the needs for these unique navigational scenarios.