No question is so simple it can not be made complicated. Pole holder? are
they gunnel mount rod holders? 1 1/8" sounds too small. Perhaps you are
talking about some out rigger holders that are placed in the gunnel. I am
just guessing what "pole holders" are but if they are to be mounted in the
gunnels, usually you will find the "covering boards" (tops of gunnels) are
cored with wood maybe 3/4" plywood or 1/2" or something. Anyway, you will
need a hole saw 1 1/8" or whatever. Replace the 1/4" dia. pilot bit that
came in your hole saw arbor with a longer 1/4" bit, maybe 6" or longer. This
is so you can guide the hole saw as it begins to cut as all the "pole
holders" are usually at 30 degree angle, so sawing the hole at this angle,
or there abouts, is part job. Without the extra long pilot you will have
great difficulty. If these pole holders turn out to be outrigger holders you
will need to put metal backing plates on the underside too. Aluminum ,or
your corner's stop sign, is good for making the backing plates. I use
backing plates on hold holders as well but unless you are after some big
mean fish you can do without the backing plates.Oh, don't even think about
not thru bolting and nyloc nuts are good because they holders tend to loosen
up after they are knocked around a bit.

--
Ron White
Boat building web address is
www.concentric.net/~knotreel