What action should be taken if there is any doubt about the risk of collision?

Answer: B — Use all means to assess and determine risk

When there is any doubt about the risk of collision, the appropriate action is to use all means available to assess and determine the risk. This approach aligns with the COLREGs (International Regulations for Preventing Collisions at Sea), which emphasize the importance of navigating safely and making informed decisions to prevent accidents. Utilizing all means includes not only visual observations but also using radar, electronic navigation systems, and sound signals. This comprehensive assessment allows for a clearer understanding of potential hazards and enhances situational awareness in busy or challenging maritime environments. By taking a proactive stance in evaluating the risk, a vessel can avoid potentially dangerous situations, ensuring safety for both itself and other vessels in the vicinity. In contrast, assuming there is no risk could lead to complacency and, ultimately, collisions. Relying solely on visual observations might not provide a complete picture, especially in poor visibility or complex navigation scenarios. Waiting for another vessel to signal could result in dangerous delays, especially when quick decisions are necessary to avoid a collision. Thus, actively assessing the situation using various methods is essential for safe navigation.