I agree with Roger
My originals are 30 degree as well as the new ones …
30 degrees in the gunwales, 15 in rocket launcher or “maybe” limited space mounting and 90 for storage.
I personally wouldn't trolling out of something less than 30 degrees.. especially bigger fish..The more vertical the holder, the more strain and pressure on your tackle…even 15 seems a little steep for a working rod holder.
I have to believe your holders are 30's but if you want to be sure Just flip the holder upside down , place the flat edge of the protractor on the mounting flange, align the middle (the index mark for using the protractor) of the flat edge with the front or back of the holder(tube) and see where it intersects on the arch of the protractor.
