Mercury - 1st Mate Safety & Security System SmartCraft Triple-Engine Kit 98-8M6007937. Overview. Triple-engine boats demand extra attention, and the 1st Mate system adds a meaningful layer of safety and security to every trip. The Mercury 98-8M6007937 Triple-Engine Kit ties directly into SmartCraft, giving the captain immediate overboard alerts and an onboard theft-deterrent that keeps engines locked when the system is armed. With its intelligent hub, dedicated harness, captain's wearable, and R