Rich - sorry to hear you guys didn't hook up.
Personally, the tuna fever has had me blow it with the fly several times.
A friend hooked up with a 4/0 Sar Mul Mac Saturday.
Based on confidence my tuna friend has and the success I've had with a certain plug - to duplicate it I would humbly suggest a 6/0 fly that stays on the top with an orange bottom. No joke. I've seen fish slam this plug!
Philster all good points - thanks. My latest issue on the fly is the braided running line I used for my 420 grain floating head - One cast awesome, second cast - yeah baby! Third cast ----- SPIDER NEST that stuff SUCKS!!
I'm just splicing it right to the 50# mono I have in front of my backing.