Not wanting to start a war on the merit of mono versus Braid. But i am wondering if others may have some ideas. i currently use 30lb .50mm diameter mono for my main line and a 50lb shock leader as i use 5 to 6 ounce sinkers. i find even with the best and smallest of knots joining the shock leader to my main line it still clunks through the guides and sometimes even jams in the spool. i have tried various knots and always trim tags as small as possible. i am wondering if i could just use say 50lb as my main line and not have a shock leader? would a 50lb mono main line effect the distance of the cast much? or do others think i should invest in say a 60lb or 80lb thin diameter braid line and have that as the main line and again no shock leader? any ideas appreciated. I should also Mention i fish off a cliff which is about 8 meters straight up, so i have to pull a fish straight out of the water i have had 20lb line break doing this. the reason i use a 50lb shock leader is that i like to do the off the ground cast using a 5 to 6 ounce sinker. 

Hey artist, 30lb main line is going to seriously hurt your distance. Alot of guys including myself use 5.5kg or 6kg main line for the extra bit of distance it gives. As for the braided main line,  can your rod fish braid? Guides, action etc... 30lb mono to 50lb mono is quite a large knot, have you tried a tapered shock leader? Also because you fish from such a high platform your length of shock leader must be quite long that will affect distance also, Is it quite rocky around your possie? Braid main line may get cut on these rocks... If it is not too rocky you could always try 6kg main line with a 50lb braid shock leader both are around .30mm so it is a super compact knot...If you try a braid shock leader crank the drag up solid and don't have the braid in the crook of your finger when casting, some guys moan about braid cutting their finger but these are the main causes if the spool slips or the braid is in the crook of your finger... as long as there is a couple of wraps on the reel and enough length in the braid leader to reach the water it should be O.K... the leader will be long but it won't cut down the distance like 50lb mono leader that long. Good luck

As Oneleg mentioned, you can glue the join between the lines- I think there's a review in the Nov NZ Fishing News about a new product for just this purpose. It involves a sleeve and an epoxy, and I think the epoxy draws the sleeve tight around the two ends of line. I think it would be interesting to experiment with supaglue on its own, too.

http://www.campbellsprotackle.com/store/product.asp?ID=1349 This is the kind of cliff gaff I had in mind. Not spring loaded at all, just flailing meathooks. Should do you proud.

Sounds like you need to buy some tapered shockleaders

I have 12lb - tapered shock leader  (15-60lb from memory - slim beauty knot) - pulley/bait clip rig

I went that way, bust offs at the join, etc etc. I went for 50lb braid/ no shock leader and it worked for me, mostly fishing off the beach. I've been experimenting with shock leaders again and are comfortable with the slim beauty and a drop of supa glue. It still rattles up the guides but if you use a good long shock leader it doesn't seem to be as bad as when the leader gets a bit shorter. It's cool to experiment as well, if you go down the path of using braid with no shock leader it does begin to weaken on the area around the top of the rod at launch, keep an eye on it during the long sessions, starts to fray, cut it off.
Casting aid? I did a couple of years good surfcasting without a casting aid and didn't have any problems with cuts on my fingers but there again I always started a session fishing in close before heading for the horizon. So it may help to start slow with the casting before punching it out wider. I used to punch it out as hard as I could without an aid with no issues. I have a casting aid now and I think they're pretty positive for your confidence even if you don't have any issues anyway.
I'm ready to drop back from the heavy stuff and was thinking of 20lb braid with a 50lb or heavier braid shockleader. The other thing is how the line you're using feels the waves and current because you've got a more positive feel to your sinker and bait you tend to 'feel' the waves and current a bit more, it takes a bit of getting use to but the rod tip can jump about a bit, if you're using a sand spike rod holder, use some pvc pipe to extend the length (but not so much that the pipe will bear the brunt of any rays/sharks that come along, it may bend or break) and get your line a bit steeper off the water.

Thanks for all the helpful advise, I will need to have a think Now as reading through there is a number of good  options. I am in the Taranaki and fish at patea Hawera and sometimes i go through to Wanganui of the mole. I find Google Earth is good for looking at points of land/rocks that stick out. as said though i use 5 - 6ounce sinkers as lots of rips along the Naki coast

I fish 0.50 mainline and 60lb - 100lb shockleaders depending on what I'm fishing for. I think the 60lb is around 0.70 diameter and I hardly hear a sound when it goes through the guides even on rods with small guides. If you're using 80 - 100lb though you can start having problems unless you ugrade the guides so the smallest is size 16 otherwise down to size 12 should be fine. The knot I use is a back to back centauri knot I think it's called.

Has someone like yeahnah actually tested casting with say 0.50mm mainline and 0.40 or 0.30 and actually measure the difference in the casts. Thinner mainline obviously gives you an advantage but I don't know how much of one, some people still cast over 150 meters with 0.50 and even 0.55 mainline with a decent sized sinker.

artist_nz seriously 8 kg mono mainline is all you need with a strike leader  2x length of your rod 15 / 25 kg experiment with knots or try a tool called Whip It, (it twists the two lines together). Also are you using a longcast reel?