Here are some observations from our skippers:
1. I would love to have a single lever morse control: I chartered a Jeanneau 35 (only reason- a C34 wasn't available) for a day with morse lever (single control for throttle and gearshift), Yanmar and saildrive. It made me look like a real expert docking into a slip with a foot to spare... Has anyone ever thought of modifying our controls to a single lever? Is it doable? Or maybe everyone loves our setup just as it is?
2. Actually Tony I prefer the dual levers. Coming down the fairway I set the rpms to 1000, cycle between F, N, R as needed. If additional thrust is needed apply a burst of throttle then back to 1000. With very little practice you can get very close to 1000 by ear not needing to look at the tach.
Sometimes current/wind will require a higher speed to get into the slip. The nice thing about the pre set spring line is that it will snug you against the finger pier as it stops forward movement, preventing smashing the bow into the dock
I've used the single lever on dockmate's Hunter with a conventional prop and dual single levers on saildrives on a chartered cat and felt like they were much more work. In my limited experience, once the shift mechanism get a worn, it is very hard to find N. Idle reverse, N, idle forward, all seem to be in the same position/detent. On the chartered cat, I physically had to pull the levers out to the neutral fast idle position to ensure the drives were disengaged.
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I've used those single levers over the years and find them to be a PITA. They eventually all become a two handed operation, which is what you have now. And I spend so much time in front of my wheel that it's two levers but only one hand at a time. You really don't need two hands to works those levers, and shouldn't be using both at the same time anyway.
I assume that new boats have them 'cuz they're cheaper to initially install.
Think hard about it before you change over.