Although i regularly land many big tuna, makos and swords with my 30's, whenever i'm catching bigger fish OR have guys that don't regularly fish offshore, i bring out the 50w, minimum. The price difference between a 30 and a 50 isn't that much, but you gain a lot by having a 50 (more drag, more line) and you only gain a little bit of weight. You won't need it all the time and most of those times you need it you won't realize it, but there are many fish were caught by inexperienced charters on my boat because of the 50s.