So after we finished the Stormsong Valley cave, we were stuck. We knew that we were looking for an object with the ID of 293843. Some people already had the great idea of tracking the cache (basically, checking if the game had loaded the item), which happens when you walks near an item. Upon checking the cache, some people already had this item, but we had no idea when and where they cached it.
Using the Wowhead client to read the cache, we started walking all around Zuldazar and Nazmir (where we assumed the next pebble would be -- A horde player who mined around Nazmir had it in their cache). We had several people roaming the zone near waterfalls, then logging out, and checking the Wowhead client to see if they could find the id. We were basically using the client as a radar.
Eventually, someone got the ID to trigger (in far north Nazmir), where we quickly saw a shipwreck. The shipwreck was way out into fatigue (most people died trying to get there), so its safe to say that finding this would have taken a lot longer without the Wowhead client and its ability to read the cache.