Jetty, Pier
You grab a tree so you can reach the bar in the ocean by making a jetty or a pier to it. Now you can walk out on the jetty and go get drinks without needing a boat or getting wet.
Imagine laying your tree into the water to make your own jetty extending out to the floating bar in the ocean. Innovative!
さん, せん
かけはし
None
You also made this jetty so it would be easier for Santa-san (さん) to dock his sleigh. Oh, you didn't know? His sleigh is more of a speed boat now, and he wants a refreshing drink after delivering all those presents. You get extra presents for making him a jetty, so win-win.
Picture Santa-san coming in from the ocean on his speedboat and docking on your jetty so he can go relax in the bar. Imagine the mountain of presents he lays on the jetty for you as thanks.