I was going to suggest that you wait for low tide
Then I looked at where you are, OH, I guess you don't have a tide there, do you? ;dAround here, like during this past week, we had a high of 11.8, and low of -2.6, which means a total tidal exchange of 14'2". At all marinas, the ramp always goes down to the dock. So especially on a minus tide, the water is way down there. Like someone had drain the pond. All you have to do is bring the boat next to the marina office, which is now at least 14' above water. Depending on the mast height, you can reach right over and get the halyard. Or you may need a step ladder.Now, on a taller mast, you gotta send someone up the stick.Yeah, we were helping our marina neighbor get his haylard down. We have tried the 2 boat hook and duct tape trick, it just didn't work too well, too top heavy. We finally used 2 PVC pipes, thin walled so it is lighter, with a PVC connector in between, and 2 PVC elbows to make a hook for the tip. It worked.