While it may look thick from overhead, it is open underneath, like a forest. This is classic Florida power fishing...7'+ med heavy to heavy rod, 65 lb braid, bobber stop, 1/2 oz to 2 oz weight, 4/0 EWG superline hook and a small creature bait.
I normally have at least 2 setups for Hydrilla.
Heavy - the super thick crap
7'9" Fenwick Swimbait rod. Lots of backbone to get them out of the crap but still has a soft tip.
Revo SXHS 7.1-1 High speed to take up slack quick
65 lb power pro hy vis yellow - sometimes the bite is nothing more than a line twitch
bobber stop - to keep the weight pinned to the bait
1.5 oz tungsten punch weight
Gamu 4/0 EWG Superline
Gambler Ugly otter, Megastrike megabug, rage lobster almost always in black/blue flake. The compact bugs get through a lot easier.
for not as thick areas or working in the holes
7'6" Abu Vendetta MH
1/2 oz to 3/4 oz tungsten bullet - this gives you a slower fall when you don't need the extra weight to pull the bait down
How?
Imagine the grass is timber or even heavier emergent (cattails for example) vegetation. You would fish the outside edge, any holes, points, endentions ect.