Not sure if I understand what you asking here, but If this helps, then use it. When you fishing offshore and you about chest deep in the surf you really don't need to cast to the ends of the earth. There is no precise yardage. You need to hunt for holes, drop offs. They can be a long way out or very close. Usually they are not that far off, but that depends on the tide and size of the sea. We were fishing in the surf a couple of months back and we were catching cob standing waist deep and casting into a hole that was about 50 meters in front of us. We were hooking them at about 20 meters in front of us. They were following the lures close by. This is where you have to be patient and never pick up your lure too soon. I hooked one cob about 6 meters from me.
On the rocks if you have a plug don't cast into the wide ocean but rather behind the waves if you looking for game fish. Game fish always feed behind the backline and that’s where you will catch a lot of Garrick and Yellow Tail. The lighter the plug, the better. If you have wind behind always go lighter. The chop on the sea makes that plug come alive and the Garrick become mesmerized. Have see too many guys with heavy tackle and 3 ounce plugs catching nothing because their plug is to heavy and does not replicate a wounded/ fleeing fish. The lighter plug, balanced rod and reel will almost get you as far as someone with heavy tackle. Hope this helps.