Which characteristic distinguishes the RB-M 45 in its design?

The characteristic that distinguishes the RB-M 45 in its design is its aluminum alloy hull construction. This material is specifically chosen for its blend of lightweight properties and strength, allowing for enhanced speed and maneuverability while maintaining structural integrity. The aluminum alloy hull also offers resistance to corrosion, which is crucial for a vessel that operates in various marine environments. This construction method supports the vessel's operational efficiency and durability, making it well-suited for the demanding conditions that search and rescue operations often entail.

In the context of its design features, while hybrid engine capability and twin hull construction are noteworthy attributes in certain vessels, they do not apply to the RB-M 45. Additionally, while the boat does have cargo capacity suitable for missions, it is not primarily distinguished by this feature compared to its significant aluminum hull construction.