For now though I shift as often as I need to or want to. Like a car it's how you use the clutch not how often.
Eric-- We shift as often as we
need to. I absolutely agree that how you use a mechanical device is a major factor in how long it lasts. But so is how often you use it.
There used to be a fellow on our dock who had a boat with a Velvet Drive. I only observed him as he was maneuvering in the fairway and into and out of his slip so I have no idea what his boat handling was like anywhere else.
He was a "shifter" and was constantly in and out of gear. I coud see that his shifting technique was fine; he wasn't yanking the levers around frantically as I've seen a fair number of boaters do. And he knew what he was doing in terms of handling his boat.
He had to have both of his transmissions repaired during the time he was on our dock and he complained that Velvet Drives had a pretty short life so I assume he'd had to have them worked on before.
Now we have no way of knowing the reason behind the transmission work he had to have done. But every mechanical thing with moving parts has a finite life. We don't know how long that life will be and its length is governed by a lot of factors. But whether it's the washer in a water faucet or the engine in a boat or the cutless bearing in a strut, it is "wearing out" every time you use it. If this was not true there would be no need for the TBO lmitations on aircraft engines and specified time intervals for airliner airframe inspections and so on.
So we engage our two Velvet Drives using the proper shifting technique, we let the prop shafts come to a stop between shifts if we can; there are some situations where we can't, and we conduct our maneuvers with minimal shifting. We shift when we need to, but over the years as we've gained experience we've learned that it really doesn't take much shifting to make a boat do what you want it to.
Not to say that our transmissions won't fail the next time we use the boat, which will be this weekend, but so far they have been trouble free for 17 years. How long will they go before needing work? I have no idea. But as long as they continue to be used they will eventually fail in some way, just like every other mechanical device that contains movng parts.