Shown below is a short pigtail of RG-59U coax cable terminated in a Snap and Seal "F" connector which is then joined to a
female-female adapter or barrel connector. The antenna shown is an Active Marine TV Antenna as used by the US Navy

The next few photos will show how this barrel connector is used in a splice and how it is waterproofed for marine use.

Above:  The second cable with connector is attached to the barrel adapter and wrench torqued. The connector on the right has an O ring in it's mouth and it is sealed to the coax internally with silicone grease.

Above:  A small roll of Coax-Seal.  It is a putty like material in tape form. The white waxed paper keeps it from sticking to its self.

Above: Note that the first wrap comes back on itself exactly and the second trun starts the diagonal wrap.  Wrap  from the coax cover toward the fitting with one half overlap with each winding.

Above: The last wrap again comes straight back over the previous wrap without a diagonal. The seal is slightly sticky and should be molded now by hand to remove any gaps and to ensure that all the wraps are blending together. At somepoint the wraps will almost fuse together and the material may have to be cut away from the cable.