We bought some chairs for the dock last year. A local guy made them out of surplus wood that is used to make kids playground structures. I can tell where he got the wood from as it has extra holes like it was originally made for other purposes. Amazingly, they are very comfortable though they don't look like it.
Problem was wind would occasionally blow them off the dock and into the water (luckily wood floats). We DO get wind here in Kansas at times. They would drift to the windward side of the pond and I would drag them out and back to the dock. But I got tired of that procedure. So I made them heavier with some surplus lumber I had, plus added a wider base so the wind would have a harder time tipping them over. So far they have not blown off the dock again yet this spring (fingers crossed).
Also decided to add some convenience shelves and fishing rod holders. The rod holders are made out of PVC pipe. I've since replaced the tin can cup holder in the picture with some nice plastic ones from Academy sports store that have both cup holder and a nice place to put lures, etc. (made for boats). Looks a little nicer and will not rust (though the tin can worked fine).
Crude? Yes. Heavy? Yes. Keeps it from blowing off the dock. Works? Oh yeah.
Yes it is kind of a crude job. But it fits my capabilities and in use have proven to work very well.
Showed my wife the pics. She told me to order two chairs with holders. I told her I would order from ya, as long as that beverage holder will accept a standard size beer can!