Enter the Gym and then press A while facing the computer thing on the lift to be taken deep down into the mine. Talk to Clyde down there and he'll give you a Fresh Water, as per usual.
Now this Gym is literally a maze! As you proceed through it, you'll light up these tiny little platforms that branch off. You can take some lifts up to get a better view of the areas you've lit up, but it may take a bit of exploring before you find the Gym Leader, Clay.
Thankfully, I've got a map handy that should help you get through the Gym in no time at all!
The "L"s on the map indicate a lift you can use if you press the button on the computer there that will show you any of the nearby areas you've lit up. The T1, T2, etc. stands for Trainers in the Gym. The dotted lines also indicate you go underneath that part.
Anyway, there are seven Workers in the Gym. I'll just put a bullet point list here along with the corresponding number on the above map:
- T1 uses a Baltoy L31.
- T2 uses a Drilbur L29, a Baltoy L29, and a Sandile L29.
- T3 uses a Drilbur L30 and a Baltoy L30.
- T4 uses a Drilbur L31.
- T5 uses a Baltoy L30 and a Sandile L30.
- T6 uses a Sandile L31.
- Lastly, T7 uses a Sandile L30 and a Drilbur L30.
In case you can't view the map for whatever reason here are the directions you need to take to get to the Gym Leader, Clay:
- From where Clyde is, go up and onto a platform thing, then cross the conveyor belt up.
- Fight the Trainer there, then head right once.
- Head down once.
- Head right once and fight the Trainer there.
- Head up, going underneath a platform, and then go up two more times (so three times total).
- Head right.
- Head down and go underneath a platform.
- Head right again.
- Head up and go underneath a platform to arrive at the Gym Leader, Clay!
Clay's band of Ground-type Pokemon can be a little tricky to take down if you're unprepared. They have higher Defense than most Pokemon, plus they all pack the Bulldoze attack, which will hit for pretty good damage as well as lower your Pokemon's Speed afterwards. That Speed decrease can be a major problem.
He leads with his Krokorok, which has Intimidate to lower your lead Pokemon's Attack stat by a stage. Keep that in mind before the battle begins and try to use a Special-based Pokemon or to switch out afterwards. It's a Dark/Ground-type, meaning it is weak to Fighting- and Bug-type attacks as well as the usual Grass- and Water-type attacks (it's unlikely you have any Ice-type attacks at this point).
His Sandslash is just an ordinary ol' Ground-type, but it has pretty high Attack and also very high Defense compared to the rest of his team. Special-based attacks are definitely the way to go against it, as your Physical-based ones will do very little to it.
Last up is his Excadrill, and this thing can demolish you if you aren't careful. It's a Ground/Steel-type mix, meaning it has a whole ton of resistances and immunities. Water-, Fighting-, and Ground-type attacks are your best bet against it. Fire-type attacks are also Super Effective, but your Fire-type Pokemon are vulnerable to its own attacks, so be very careful! Excadrill has outrageously high Attack, great HP, and it is also very fast. Thankfully, aside from the resistances its types give it, it doesn't have all that great of defenses, so hit as hard as you can. Grass-type attacks are also fairly effective, even though they aren't Super Effective against it (and Grass-type Pokemon resist Ground-type attacks, so Excadrill may not even use Bulldoze against you).
After you beat him, you'll be rewarded with the Quake Badge, which ensures traded Pokemon up to level 60 obey you without question. He'll also give you TM78 (Bulldoze). It's a Ground-type attack that hits for moderate damage, but lowers the foe's Speed afterwards. Since Ground-type Pokemon tend to be a little slower, sometimes that Speed lowering gives the Ground-type Pokemon enough Speed to outspeed the Pokemon, which is great if it would take two attacks to knock out a Pokemon anyway. It may be better than Dig for moderately (but not severely) slow Pokemon.
He'll be kind enough to use his private lift to take you out of the Gym afterwards.
Outside, Hugh will be waiting there, as will Clay. They'll talk for a bit, and then Clay will head off over to the Pokemon World Tournament, telling you two that you should take part as well. Needless to say, that's all it takes for Hugh to run off.
Well, heal up your Pokemon, and then head on south to the Pokemon World Tournament!