If your Karve is partially loaded, the Karve in a box technique can be a bit of a pain - this is especially true for Longship.

As long as you aren't close to swamp or plains you can use a raft to extend your swimming range. This allows you to park your ship much farther from shore. Think of the raft as a water ladder.

Once you've parked your partially loaded ship, use 'raft in a box' while you are out exploring.