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.
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.