My 1st day surfcasting ended early because of the raw fingertip so I gets me a cannon .......which took a bit more "learnin " than expected
I found that the position of the cannon should be pretty much adjacent to the spool , to far up the rod dont work .
The other thing I learnt was that the amount of oomph one puts into the cast verses the distance the rig flies is one of them diminishing return things , and by putting in half the effort the rig will go 3/4 the same distance without degloving your finger and anyhow most of the fish are not that far off shore.
Im fairly new to surfcasting but I have 50lb braid and 2 rod lengths of 30lb fluro , and I did find the cannon needs a bit of practice and I aint sure (yet ) if Im going to keep using it . If you really need the distance its probly worth persevering

Check out some vids of long distance casting competitions ..... these guys make it look easy .
I wish I was young again .... Id be heaps smarter than this time