Volt doesn't sell marine grade wiring. Is there any real advantages of using a 12 gauge marine grade wiring over direct bury cable?
IMO, it’s major overkill and may not be practical. Marine grade wire is reinforced to withstand harsh above ground conditions like strong sunlight, moisture, salt, high temperatures, oil, and vibration. Another issue is that it’s strands are somewhat thicker than the same gauge of landscape lighting cable. So I suspect you might have issues with wire connections both when using hubs and at your transformer taps. Further, because the two different cable types are stranded differently, I suspect there’d be electrical conductivity (voltage drop)differences that could cause problems. For more definitive answers and to make sure you don’t void your warranty, it’s probably a good idea to contact VOLT customer service. As long as it’s buried, landscape lighting cable should be durable enough to withstand whatever weather conditions you’re likely to encounter.
My contractor wants to use the Marine grade. He has been straight with me but I think it is overkill too. I think I will go with 12/2 by Volt.
