Possible sling
I launched my Zuma and AquaFinn using a towing strap from the automtive section in Walmart. I would sling it under the boat and up the sides about mid-boat, the balancing point, hook the rings in the hoist hook, then run a line with a snap hook from the hoist hook to the bow. This worked fine for those but with the 170 someone recommended hooking off the chain plates and the stern cleats. Going from starboard to port on each and bringing the two lines/straps together in the center to hook off the hoist hook. I haven't tried it yet but it is giving me room for thought.
