Hi Craig, Replace wires every 10 years, just to replace wires? No! You need a valid reason for replacing your wires. What you have to keep an eye on are the swages at the fittings. That is the usual place of failure, because of corrosion inside the fitting which leads to a split in the swage area - which you can see. (if in doubt, us a 10X magnifying glass or loupe) The wire itself shows deterioration if you find broken strands poking out. These are the famous (infamous) "meathooks". You will instantly know what I mean if you run the wire through your hand and find one! I still had all my original standing rigging on my big boat after 26 years of ownership - no swage failures - no swage cracks - no meathooks. But I did have an incipient failure in a swaged pelican hook fitting on my lifeline. The wire, where it entered the pelican hook showed signs of rust, and when I examined it more closely and bent it back and forth, it did come apart, just at the end of the fitting. So, if you see rust spots - Check; and keep checking if you find meathooks - replace (the wire may still be more than adequate but why risk injury?) if everything seems OK, then keep using the rigging. Connie