I fished all the way out to Proteus this past weekend. The water was dirty at every rig on the way out to include the Proteus. Heard radio chatter from charter captains complaining about the water clarity and bite.
We had no problem catching bottom fish on the way out and catching tuna at the drillship. Yes, water clarity is a factor in catching tuna at or near the surface. Remember that dirty water usually stays in the upper column. Tuna prefer clear water so they can see the squid and flying fish at or near the surface in the evening.
When we encounter water in these condition, we just add egg sinkers and go deep, like 180-240'. Obviously chunking in these conditions is difficult and rarely productive, so go deep.
I'm looking to go back out 30 Jun/1 Jul and fully expect to see dirty water. I'll employ the above tactic and throw in some deep diving lures, stretch 30's. The tuna are almost always there, just have to find a good way to reach them with the right bait presentation. Hey, they have to eat, so go get them when you can.
Tight Lines!