You get it from Captain Stern in Slateport City after finding the Scanner in the Abandoned Ship but you need a Pokemon with Dive.
First you need to go through the abandoned ship and get a scanner from a scientist in there Note: need dive, then give the scanner to captain stern and he will allow you to choose either a deepsea scale or deepsea tooth obviously you want the tooth. Finally have a clamperl hold the deepsea tooth then trade it to a friend then take it back and it will be huntail, if you chose the scale you will get gorebyss instead of huntail.
There is a store called Scuba Dive that sells equipment and gear in Ocean City
dive
You can find great deals of dive gear from any specialist dive store in Ontario. These include Dave's Dive Shop, and Groundhog Divers, among other stores.
To dive for Cap'n Salty's lost lobster trap at Puffin Point, you need diving gear. Catch the old photo that is blowing in the air by the lighthouse, and swap it for diving gear at the Say Cheese photo shop.
deepsea tooth gets you huntail while deepsea scale gets you gorebyss. You can decide which on you think is better now.
Deepsea skate was created in 1896.
There are a number of on-line providers for dive gear. including www.leisurepro.com/ www.divers-supply.com/ You could also do a quick search for suppliers in your area.
You need the diving gear from the Say Cheese photo shop. Catch the old photo that is blowing in the wind next to the left side of the Lighthouse. You can trade it for the diving gear, then dive at Puffin Point to recover Cap'n Salty's lobster trap.
The website titled the best scuba dive gear has a lot of good information on scuba gear in general. They have a section describing the various types of dive lights and which is best in different situations.
You need to have the gear if you do put it on from your ineventory and go tothe water and there will be a button dive your now in the water! === ===