If your former coworker was sliding his hands while paddling he had a too short paddle – I have one that is INTENDED to be used that way, a 72" “storm” Greenland paddle (which came with my skin on frame). In fact I often carry it as my backup “spare” paddle on the deck. The reason to switch to a storm paddle is when conditions get really windy you have very little blade surface up into the wind while paddling – similar principle to some people switching a two piece Euro paddle to a 30 degree offset in wind: the narrow edge of the Euro blade faces wind on the up end of each stroke instead of the flat face. You use a sliding stroke so that you have the full depth of the blade in the water on the stoke side but little sticking up on the high side. With a properly sized regular GP your hands stay on the loom without sliding while paddling.
My cedar one piece GP was custom made for me by a craftsman out in the San Juan islands who specialized in them. He took a number of measurements from me (of both me and the kayak I was going to mostly use the paddle with, or at least I expected that at the time) . I chose a horizontally laminated model based on his ratings of relative flexibility and strength, He made paddles from solid cedar, horizontal cedar and Douglas fir laminates of 3 or 5 layers and also 5 layer vertical laminates (the stiffest). I chose a shoulderless design where the shaft gradually widens into the blade – some GP’s have a squared off shoulder where the shaft loom transitions to the blade portion. The loom is the portion where you place your hands. Your natural loom measurement is one of the metrics for making a paddle, as is the diameter of your grip. I’m on the smaller size as a person (5’ 4") but have relatively long hands, fingers and thumbs so my oval shaft diameter is pretty standard.
Since over my active lifetime I have broken both wrists (right one still has 3 screws) and my left elbow and proximal humerus, I have learned that I do best with narrow bladed paddles. I have Werners and Aquabounds with relatively slim blades – sorry, no model names on these because they are older and several were obtained as parts of package deals on used boats but the blades are 19’ x 6" . I have one Cannon (a 4 piece carbon shaft I bought for packing one of my smaller folding kayak kits for airline travel) that has a slightly wider blade than the others (19" x 7.5") – don’t much care for it for any extended outing or one where I need sustained speed over distance – it was fine for poking around narrow winding British rural rivers during my trip there in 2017. Too much strain on the assorted upper body joints with larger blades.
AI also have a vintage Bending Branches two piece wood paddle, vertical 5 layer laminate that is made of some kind of very fine grained blonde wood (maybe white cedar?). It has very long narrow blades of 23" x 5.5". I do like the feel of it but at 230 cm it’s a little long for usual preference with my kayaks (which are mostly Greenland style with 20" to 23" beams). I do use it with my 26" beam solo canoe.
Back to Greenland paddles. I had a Northern Lights 3 piece carbon GP for a while but never liked it that much. It was shouldered and the loom didn’t feel right to me so I sold it to another folding kayak owner who needed a breakdown GP for air travel.
The carbon GP I have now is a GearLab Akiak model, which has almost exactly the same dimensions and weight as my beloved original cedar/fir GP. I do like it and it’s great for travel (I found it fits perfectly in a padded rifle case). It feels very much like the cedar/fir GP but not exactly.
So, by far my favorite paddle is that wood Greenland and the one I use most often I had it at one of the 4 day Greenland training camp events where the participants enjoy swapping gear with each other to get the feel of other designs. Quite a few long time GP users and instructors there tried it out and highly praised the feel and performance so I guess it’s really as nice of a paddle as I have always felt it to be. Unfortunately the paddle maker, David of Friday Harbor Paddles, quit the business many years ago due to chronic stress damage to his hands and joints from woodworking. There are still some folks out there who make custom wood paddles to order. I feel like I really lucked out finding him for my first GP. I’ve loaned it to a couple of people to take measurements off of it to duplicate the lines. That paddle is in need of some restoration right now – I used it paddling along Maine coastal inlets two weeks ago and scratched up the ends a bit levering out of rocks . It’s due to be sanded down and resealed (tung oil and varnish mix). I have never had any joint pain or fatigue using this paddle, no matter how long I was out or in what kind of conditions. But I am not often out in extremely challenging waters, nor am I much interested in speed.
By the way, wood is really buoyant and my wood paddle has proven helpful in learning to balance brace and in rolling practice. It is the one paddle I would never give up. I mostly keep the others to use as loaners, spares or for specific functions (like with the canoe or for airline travel).
You’d have to register (free) on the qajaqusa.org Greenland style kayaking site to post on their forums, but you could “lurk” and find endless exchanges on the making and merits of GP’s and other trad paddles.