If you are going to look for shipwrecks, and plan to look in several grids, do yourself a favor and visit your animal pen to pick up some suicide pills, also known as poop. Put them in a box, or smithy, or anything you can store them in. Use your sextant, and search for the shipwrecks. Then, after crossing into a new grid, eat the poop to kill yourself quickly. Respawn, grab your gear, and redo the sextant buff.
Crossing into a new grid causes a bug. The wrecks are are not where they appear on the map. Plus, you can't redo the sextant buff until it has expired. Respawning resets the buff, so you can redo it.