Is it possible to launch from a ramp? Yes.

Is it convenient? No.

Is it safe? In my opinion and experience? No.

Our boats are lightweight and do not take to being "beaten" against a dock one launched. I still have a soft spot in my hull due to this fact. No motor or auxiliary power means that maneuverability after launching is greatly reduced resulting in damage to others' property or to other people around the ramp area.

Furthermore, the biggest challenge is getting back to the dock once you're finished. If the angle of the dock/ramp to the wind is bad, then it could be quite difficult for a novice to dock his cat there, especially since our ability to "slow down" is very limited.

I've launched from ramps/docks before. Launching from the beach, or in your case, walking the boat from a ramp to a beach, is much much better. A place to land safely is really the sticking point IMO.