Over the years I've worked with a number of owners who do their own work . Occasionally a boat owner starts off on a project themselves  and discovers that they're into a bit more work than they originally anticipated , and call me up for an evaluation .  Initially my evaluation is not usually what they want to hear . In this case the owner was closely involved with the project , and got a first hand view of what was going on as things progressed , and by the end realized that I was probably right in countering his initial suggestion of changing ten to fifteen ribs , to my initial evaluation of replacing the whole bottom . Here is the boat being unloaded in my shop with a lot of the initial preparation already done by the owner .

 The initial phase of replacing a bottom in a boat like this is to replace all of the ribs . In the case of this boat the covering boards were removed to simplify the installation of the new ribs . It is possible to re-rib a boat without removing the covering boards  , but in this case the covering boards were in pretty bad shape . The time saved in replacing the ribs with the covering boards off paid for a large part of replacing the covering boards later on . As the old ribs were removed the inside of the planking was cleaned up . Cleaning up the planking without the ribs in the way is also a savings in the big picture .