I don't know what a grind is. So far, I have found one sunken crypt and got about 80 ingots of iron while dying three times. So I need to keep exploring and finding more swamps and sunken crypts.

Copper and tin mining is certainly not a grind if you organize it. Iron looks as though it's going to require lots of exploration. I hate exploration. Riding in a karve with a good wind to to reach new islands.