This is a guide I made to help out a friend, I might re-do it and go more in depth but for now it's as it is
At 50% Health and below, receive 20% increased healing.
Standing near a Short Cut Heals you for 200 health every 1s
Heal for 400 Health when hitting Harpoon.
Your first jump within 1s of exiting Short Cut will be higher.
Hitting with Harpoon generates 1 ammo.
Your weapon attacks deal 225% increased Damage to Shields.
Your weapon shots reduce the effect of healing on your target by 90% for 1.5s.
With the hurl talent you'll be able to have a lot better confirmable damage at range than with your standard primary fire, with Mortal Skewer you're able to stay in the back-line and sustain yourself since it activates the heal when hitting "anything" deployables, shields, you name it. Sea Dogs helps you in duels or out-poking someone if they decide to dive you along with Dark Bargain. Expansive Vault is for vertical mobility and Cursed Weaponry is so you don't get caught on dredge's long reload mid-fight.
For items Dredge is a little interesting, for the offensive items you'll either go Cauterize or Wrecker, for someone beginning on Dredge I would go Wrecker since his Harpoon doesn't apply cauterize and it's much easier to hit a shield than a person with his bombs. Once you get used to his weapon then feel free to buy both to help your team.
You don't want to get too close to your enemies with dredge unless you absolutely have to, with hurl you have the range to sit back and snipe since your harpoons have no damage drop off and it takes 3 shots too kill a champion with 2400hp (health cards not taken into consideration). As Dredge you also hate flankers particularly, Androxus and Evie who can dive you very easily so make sure you're positioning yourself where your team can help you if you get dove on.