Which maritime buoy would be used to mark a speed restriction area?

The use of a buoy to indicate a speed restriction area aligns with the purpose of Special Marks within the IALA Maritime Buoyage System. Special Marks are designed to convey information other than the traditional navigation aids, such as indicating areas of special significance or caution. This includes speed restrictions, no anchoring zones, or other regulatory areas that need to be acknowledged by mariners.

Special Marks are typically yellow, which visually distinguishes them from other buoy types, making it easier for navigators to recognize the message they convey. They may also be fitted with additional symbols or signage that indicate the specific restrictions or guidelines associated with their area.

In contrast, Safe Water Marks serve to indicate that there is navigable water all around the mark; Lateral Marks are used to indicate the edges of navigable channels, helping vessels to navigate towards or away from shore; and Isolated Danger Marks mark hazards that can be safely passed on either side, but do not provide regulatory or cautionary information regarding speed or other specific rules.

Therefore, Special Marks are appropriately used to alert mariners to speed restrictions or similar regulations.