The coordinates from the locker are just the degrees, not the full degrees and minutes. So, they define one corner of a 1 degree by 1 degree square
Each step can be 4-6 minutes of latitude or longitude, so that's a 10-15 x 10-15 square to search.
- If the coordinates are yN xE (the x & y being the numbers), then that is the bottom left corner of the box.
- If they are yN xW, the listed spot is the bottom right corner of the box
- yS xE is the top left corner.
- yS xW is the top right corner.
- If you have trouble visualizing them, use a compass or the UOAssist command -where in the CC to find them, and mark them.
From there, it's just a matter of exploring the box. At GM Cartography, you have a dig range where standing at the approximate middle and digging the 4 cardinal directions has a good chance of finding it, or you can do like I do and start in one corner and mow the yard, digging in the two directions into the square every 4-5 steps, then stepping 4 down and crossing back (repeating the process) if you don't find it while crossing.