My walker bay is mounted in the same position, although it's only ~70 pounds. One of the big things is to be careful when the wind
is kicking up, and if you slide it along the gunwales to put a little towel down or something so it doesn't grind its way down. You can hoist up the bow and then "walk" the stern overboard
, or you can build a four point bridle
No matter what I end up getting a bit of water
in it each time but it's gotten to be pretty easy. I can launch without too much hassle in under 10-15 minutes.