Originally Posted by Winemaker2
I guess I dont see the advantages of welding wire in an application where the wire is run once and fastened in place. Flex can actually hurt you unless it is very well secured more closely so it doesn't flex. For marine applications welding wire is not recommended due to the vibration and potential flex adjacent to a secured location.
Sometimes cable has to flex. The battery tray on my current motor home extends 24". Controlling welding cable was relatively easy with springs and saddles to support the cables. I did another sliding battery tray that was much more confined and used welding cable inside pieces of flexible conduit clamped together so they moved like a drag chain.
Sometimes it's nice when cable flexes. When you upgrade and have to drag 14 ft of 3/0 cable where the #2 was originally routed (during, not after, construction) flexibility is really nice. There are reasons to use welding cable.
RVs aren't recommended for marine applications either. I'd be willing to bet if you put a hull under an RV and start flying across the water the welding cable would be fine after the RV had disintegrated. Problems in one machine aren't necessarily a serious concern in another.