...a lot of work! I had the Hinckley yard in Portsmouth RI soda blast the bottom. They use an outside contractor for the work and he did a nice job, stopping when he could at the barrier coat as I requested. I have done the rest myself. My thanks go to the people at Hinckley who have graciously allowed me to take on this project myself while in their yard. They could not have been more helpful or friendly! I hired them to perform a couple of other jobs while I am there so hopefully they make a couple of dollars on this project...

I will do my best to break down cost and time for you.

About $2800.00 for hauling out and soda blasting the bottom.
$1200 for a beautiful Festool sander and vacuum system (an amazing combination, nicest I have ever used if heavy to hold above your head for days at a time...).
Each coat of InterProtect 2000e required about 2 gallons of product.
Each coat of Hydrocoat ECO required a little less than a gallon.

Time spent? I am trying to forget the hours as they are not easy hours!
About 2 days sanding the bottom after the soda blasting. This was a process of sand for a couple minutes rest for a minute, repeat, repeat, repeat until everything is smooth and sanded. It was not much fun...
Each coat of barrier coat took in the order of 3 hours to apply.
Another couple of days sanding again after the five coats where on and then I began applying the bottom paint.
The bottom paint went on with more care as I was rolling and tipping as I went so I would say between 3 and 4 hours per coat.

I have a very smooth bottom now but I will still sand the bottom paint one last time. As I am no longer sanding bare gelcoat or barrier coat I expect this step will be easier than what preceded it. I still expect to spend a couple of days sanding though.

I did a practice run of the job on our Trinka dinghy so I know that the bottom paint will be pretty easy...

I will have been at this for the best part of a month by the time the boat bottom is done. It is a lot of work but I will have saved the best part of $10,000 when I am done and I will own a very nice new sander and vacuum.

Not everyone needs or wants such a smooth bottom so much time can be saved here by simply not sanding... I have lived with a smooth bottom on this boat from the time it was new so I simply did not want to take the boat "backwards"... I did find that if the barrier coat was thinned about 10% and applied with a foam roller it was much smoother (thus easier to sand) but I got reprimanded by the people at Interlux who warned me that I was doing bad things so the final 3 coats went on thick with lots of texture....

It is quite gratifying to have people who do this for a living stop by while I am working and say "wow, nice bottom!" I did not exactly enjoy the process but the results are becoming exactly what I was trying to achieve.
Bruce