Antenna

I am about to replace the VHF cable in my mast. RG 8X is presently in the mast. I am thinking of replacing it with RG 8U or RG 213U or should I replace? I have several options: 1) replace the old cable with RG 8X. 2) replace with RG 8U 3) replace with RG 213UAny comments or recommendations?
Thanks in advance.
Ed Kittiwake, 1974 C&C 30

I replaced my RG-8X with RG 8U with 8 years ago after not being happy with my VHF performance 30+ miles offshore. I am very satisfied with the $ and effort required to pull that "monster" cable thru... Be sure you attach a very strong leader/line to the old cable when you pull it out of the mast AND out of the boat bowels - so you can pull this big stuff back thru.