
No, not really. The Drive can lose any combination of cables as long as one of the chain-cables remains functional, and the Drive will still operate. In the case shown here, the front cable broke after well over 1000 miles of service, temporarily unseating the idler cable. As a result, the pedals could collapse backwards, but still operate normally forward, driving the rear fin.
Of course, if the rear cable were to break and the idler cable become unseated, the pedals could collapse forward. Then you would merely reverse the Drive and operate the boat backwards to get home.
Running with one fin in any case, the boat will rock back and forth, but you can quickly adapt to the motion and still be able to use the Drive to get home. This next picture shows the GPS track of an Adventure running with one fin at "fast cruise". Obviously a little slower with less thrust available, it nevertheless propels the boat quite adequately when properly tuned and adjusted (especially with a Turbofin).

Something to keep in mind if and when you might experience a "Drive failure". The only 2 conditions that I am aware of that would totally disable the Drive are losing both chain cables or losing both fins, neither of I've ever heard of occurring with factory equipment. Anything short of that, you're still in business (unless you'd
rather paddle)!
Knowing how to respond ahead of time can save you a lot of trouble.
