In Nancy Drew: Sea of Darkness, the last paragraph of Magnus’s journal mentions the sounding numbers and locator compass. There are two broken pieces of the compass to find: one is on the captain’s table in the quarters, the other hidden in the ship’s wheel.
To find the sounding numbers, place the pins on the map according to the answer found in the crossword from the desk, which results to 14. Another number is indicated in Magnus’s letter found in the dog toy drawer in the cabin. This one mentions scraping barnacles off a pylon at the dock. Change the time of the day to Low tide and climb down the ladder to the dinghy. Use the utilihook (found at the fish cleaning station) to scrape off the barnacles. The number 26 is found.
Lastly, climb the crow’s nest on the ship to find the number 86 carved into the mast. You may need to revisit this, even if you have been here before.
Re-enter the wheelhouse and look at the sounding charts to the left. Be sure that you are looking at the chart on the left, from 1784.
Using the locator compass, hover over the sounding numbers so that they appear in the 3 outer rings and center ring. Look for 11 and 14 and find the other two numbers that can add with those to make 86. You can place the compass on the chart to check your work when it lights up.
See the video for the exact location.
When Nancy exclaims that it is correct, use these numbers down in the captain’s quarters. Look in the cupboard for the number dial and punch in each of those four numbers from smallest to largest: 11, 14, 26, 35. Some mechanical sounds are heard when you enter them in correctly.
