... and I have Tapatalk on my tablet. I went into each "category", looked at the threads in each category (General Discussion, boating, etc.), read the ones I wanted to read, and then clicked on mark forums read. It marked each unread thread in that category as read. This gave me the best of both worlds...I got to read the threads of interest to me, and get rid of those en-mass of those of no interest.
Of course if you don't have Tapatalk, all this is of no use.