Mercury – GPS Extension Cable | 9.8-Foot CAN P Line | 84-879171T23Mercury GPS Extension Cable 9. 8 Foot CAN P Line 84 879171T23 Overview Longer boats and wider helm layouts sometimes need more reach than the factory GPS cable provides. The Mercury 84 879171T23 Extension Cable adds 9. 8 feet to the GPS line used with the 8M0024918 kit, giving you enough length to route the antenna cleanly across larger consoles or more spread out rigging paths. Built for CAN P GPS systems without an Auto Pilot module, it extends the