I've been shark fishing in the surf for over a year now, but I'm new to kayaking and dropping baits with large reels and whatnot. I'm having a problem that is costing me ALL of my catches. Let me know what you think, I could use the advice.
This is what happens: The clicker starts going bananas and I look at my fishing buddy and say "Ready to rumble?!?" I get out of the chair and grab the rod out of the sand spike. I take a few seconds to A) gather my cool so I don't do anything stupid from the excitement and to B) let the shark take the bait/hook. I tell myself "Here we go", I put my thumb on the spool (Penn 9/0) and run back 20 feet in an effort to set the circle hook deeper for the upcoming battle. After that, I walk back to the sand spike tightening my drag and taking in any line I may have just brought in only to find that the shark is clearly swimming towards me. Why else would the line be coming in so easily? I keep reeling furiously until my buddy tells me that the line broke and I can stop now. Then we swear and cuss a lot.
During the past two fishing trips I've gone on, I've lost every shark to a line break. That's a LOT of sharks in the month of February alone. Me and MrAnsel lost 11 in just one day during the Blacktip Challenge and that's seriously frustrating during a tournament. So I figured it was the 50 lb. mono I had on my reels and replaced it with 80 lb. test. We just took it out fishing the other day and the same thing happened. When the line comes in there are some signs of abrasion, but nothing crazy.
What do you think is happening? What are some fixes to a problem like this? Thanks for the help.
What kind of rig are you using and how long? I'm getting tired of everyone looking at post and not replying.
Couple things. Are you using a topshot? I run 50lb mono on my 9/0's, with a 100yd topshot of 80lb test. My guess though is that the problem lies in your leaders. Your chafing section is probably not long enough, or maybe it's your wire. Run 5' of wire. Any less, and you risk the shark swallowing the whole thing and biting through the mono. Make sure your chafing leader is at least 10' long. Tail whip will wear through 50lb mono in a hurry. Provide more details about your terminal tackle and I can help you better.
Other Than Deteariated Line I Can Only Imange Maybe Its Getting Caught On The Spool 
Thanks for the hit, Tom. I'm using an 18/0 Lingren Pitman circle hook, 6 feet of 500 lb. cable, 400 lb. crane swivel, 15 feet of 400 lb. mono with a snap swivel on it for a sliding concrete weight, another 400 lb. crane swivel and then my line tied on with a proper uni knot.
http://www.basspro.com/Offshore-Angler-Tight-Line-1/2-lb-Spools/product/22335/
By the way, this is the line I'm using. Does anybody have experience it? It's Bass Pro Shops brand of saltwater mono line. I didn't see any bad online reviews, it's $10 for a half pound and Bass Pro is an easy drive from my house. On paper it looks like a great deal, but it could be a bad product. Not sure.
The line is brand new, fresh out of the package.
It really shouldn't be the line, and everything you've listed sounds good. The weird part is that it's consistent, so it's not rubbing on some lost crab pot or random rock or something. I don't know what to tell you. Maybe you have the concrete breakaway rigged up in such a way that it rubs the line? I don't know. It is the mainline that's breaking, right?
I've Used That line Before & Its Pretty Durable 
Rudy, that's correct. It's the main line that's breaking, not the leader. It wouldn't be the weight, that would be at the other end of the 15' mono leader.
JPSHARK, thanks for the confidence. The wear I saw the other day was as if someone rubbed it once or twice with sandpaper. There aren't any serious nicks in it.
Maybe it's knot failure? I could try and crimp the line onto the leader instead of tying it?
Maybe I could try a Dacron braid for better knot retention and still have some abrasion resistance (at least better than a spectra braid)?
I Think If Its Your Knots Tie A Slip In It To Catch The Main Knot, But I Would Check My Spool To Make Sure Its Not Spreading 
Only Other Thing I Can Think Is Your Tinsle Strength On Your Mono
Thanks for the tips, guys. If the line I'm using is good stuff, I'll try some different knots. Rudy, you suggested it could be something underwater tearing up the line. In a few weeks, I'll be going to a totally different location on the west coast, might be the ticket.
I'm still open to solutions. Thanks again.
Where on the west coast?
Haven't decided yet. Maybe St. Petes.
a lot of great response to your question. thanks everyone. I think the next step would be to have someone go with us next time we try that area. Maybe they can see something we are missing.
My only thought is that either A: when you grab the spool and run back to set the hook, you are putting too much strain on the mono and it breaks
or B: often times blacktips will circle around and bite through your mainline, they can be very smart like this. I've lost a bunch of rigs due to this lately catching the schooling blacktips in the SE.
It can get real frustrating!!