You will need the Dive HM which I think you get from Stephen after getting the badge from the Mossdeep gym. Then use Dive out at sea and you can find shards underwater aorund the Mossdeep and Sootopolis areas.
You don't need a Red Shard for Dive.
you can find it on route 124 I've had a vulpix and to make it evolve i had find the red shard and i had to give it to hunter in mossdep city to get the fire stone
Red shards can be found all over underwater areas
to get a red shard in emerald, you have to go to route 124. Hope this helped You have to dive underwater using hm dive and find them hidden in pale couloured stones, such as those you see in caves
First find a Red shard underwater you can find dive spots that lead to red shards near the hunters house which is west from mossdeep city trade the red shard to the hunter to get a fire stone.
find it using dive
find one in the firey path or trade 1 red shard for one at the hunter's house
I found a red shard after using CUT on a few trees, it was lying around as an item. Was near Rustburo i think.
u gotta find a red shard & give it to Hunter to the left of mossdeep city. He lives on an island with one house on it.
You Have To Dive N Look For Them It May Be Hard But Worth It In The End(:
its near the northwest corner of the route.
That can be found underwater near the hunter's house west of mossdeep city.