That said, we are at what I believe may be a turning point in the history of saildrives. The major drive manufacturers in the United States, Yanmar and Volvo Penta, recommend replacement of the bladder seals every five and seven years, respectively. But based on my research of some major full-service boatyards, people are not having the work done at the recommended intervals. In fact, a quick scan of some of the major online forums brought me to the J/109 group, where this topic is a major discussion point. It seems many owners are going 10 years and longer before replacing the outer and inner bladder seals on their saildrives. Cost is probably the driving reason for the delay. Pricing that I found varied from $2,500 to $4,000, depending upon the drive’s location and how it was installed. Own a catamaran? Multiply by two.