I was recently looking for a lifeguard reach pole for my new lake association beach safety board. Minimal official lifeguard reach poles start at $60 and go up to to nearly $200. But at Ollies, in the mop and broom section, I found a 12' extension pole for $15. Threaded end is meant for painting ceilings or whatever, I guess. I attached a colorful rope loop and hung it on the safety board at the beach. Fiberglass with an aluminum telescoping extension, very stiff and lightweight. I bet it would work great for poling a boat. If you have an Ollies nearby, check it out. "Good stuff cheap".
I have an expandable aluminum pool cleaning pole with a friction adjuster. I would never trust it to hold under the pressure exerted while poling. if the friction sleeve were to slip while poling hard the result could (and probably would) be catastrophic!