Many people these days are looking towards synthetics or to un-coated stainless steel to replace their lifelines over the traditional vinyl coated lifelines of the past. First, let’s talk a little bit about the cons of using vinyl coated wire: the wire cannot be visually inspected for failure, the wire is typically made from a weaker (but more flexible) construction wire like 7×7 or 7×19 instead of 1×19. This also usually means that the grade of stainless steel used is a lower 304 Â architectural grade instead of the preferred 316 marine grade. Â When making a set of vinyl coated lifelines the time spent cutting-back vinyl to accommodate fittings is greater, resulting in greater cost. Lastly, the cost of vinyl coated wire is more than un-coated wire.
Using un-coated wire is now also an offshore equipment requirement for any boats in a race sanctioned by ISAF
When comparing synthetic lifelines vs. stainless steel un-coated wire. Stainless steel 1×19 un-coated lifelines typically come with swaged, mechanical or hand-crimp end fittings that are made by Hayn, CSJohnson, Suncor and the like. Synthetic lifelines are usually made from Spectra, Dyneema, Dynex Dux, or other similar fibers. These synthetic lines are to be spliced and whipped to an appropriate terminal provided by CSJohnson or Colligo Marine. As an alternative it can be simply spliced, lashed and taped.
Assuming the boats’ stanchions, gates and railings are ready to have either synthetic or stainless lifelines installed, then we can make these following statements: 316 grade stainless steel offers roughly 7-17 years of dura-ability based on geographical location and wear. Although a fairly new concept, a coated synthetic like Dyneema can offer a life span probably more in the 4-7 year range. If using stainless hardware, you can probably expect re-use the hardware through roughly two life cycles of the fiber rope.  
In general, the install time for a professional using stainless wire, from measurement up until the final tune for a standard 38′ cruiser with port and starboard mid-ship double gates, would be around 6 hrs. The same install time for a professional using synthetic lifelines, from measurement up until final tune for standard 38′ cruiser, would be at least 8 hrs (if you’re good).  
Material costs for this standard 38′ cruiser can be expected to come in at around the same price for both the synthetic and the stainless steel option, depending on the type of hardware used (or not used, if you are doing the lashing thing). If anything, you can figure on the cost being slightly more for the synthetic rope, if using the recommended hardware/terminals.   
Again, all of this is assuming that the boats stanchions, gates and railings are in proper order and ready to have either synthetic or stainless lifelines installed.  You should be aware that most stanchions aren’t ready to be rigged with synthetic rope. Despite Dynex Dux’s chafe resistance, it is no match to that of stainless steel wire.  Extra precaution 
needs to be taken to ensure all stanchions have ferrules and are inspected for a clean lead. A chafe guard of some sort may be recommended at all of the stanchion cross-thru points to prevent chafe. Boats with more fore and aft shear curve (mono-hulls) are at greater risk of chafe vs. more straight line hulls (catamarans).
NOTE: Stainless steel coated lifelines will require a minimum of a 3/8″ stanchion hole for a 3/16″ wire swage to fit. Un-coated. When outfitting your boat with 1/4″ wire, a special swage fitting which utilizes a 7/32″ die may be necessary to pass through the 3/8″ ferrule.
In conclusion stainless steel wire is cost effective in that it is; virtually maintenance free, promises a long life expectancy and is most likely the best ‘bang for your buck’. Fiber rigging (done right!)  can really add a beautiful custom and unique accent to your yacht.  Keep in mind, any of the aforementioned  lifelines will look stunning when newly installed.  Just like with anything else, proper maintenance and inspection are the key to their longevity.
Need some help deciding which lifelines are right for you? Drop us a line we would be glad to consult.
Thanks for the interesting write-up. I am getting ready to replace my lifelines on an ’83 Watkins 27′, replacing vinyl coated SS. I have two questions:
-For synthetics passing through my old stanchions, is there a recommended ferrule available that works with this line? I didn’t see a link in the article. I don’t much like the idea of using tape as a chafe preventive, for both safety and esthetic reasons (my jaw-droppingly beautiful yacht have tape on it??? )
-Is lashing a spliced thimble preferable to simply using a strap hitch on some type of loop (like a brummel) when attaching the fixed end of the line?
…and thank you for the comment. Yes, all good questions. Ronstan used to make white plastic, snap-in, ferrules that might work. Also cutting the approriate ID tubing (probably 3/8″ ID) to l-1/2″ pieces and “belling’ or flaring them into the hole might be a good idea. Welding-in ferrules and then fairing the weld is the professional method. Then a piece of marine grade heat shrink where they pass through the stanchion would also not be a bad idea. Easy on the heat Dyneema is heat sensitive!!
The lifeline course can start via a strap hitch (aka cow hitch, bag tag) directly to the forward pulpit via a brummel splice with a large eye. Then led aft, brummel spliced again (small size eye) and then lashed to the stern rail using smaller diameter dyneema. This is the adjusting end. DO NOT USE THIMBLES, they are unnecessary. I still recommend using CSherman Johnson splice line fittings as described in the article. This in conjunction with welded-in stanchion ferrules and a heat shrink service at the stanchion cross-thru point offers the most professional install.
Hope This Helps,
T.R.C.
Excellent well presented post with some very useful information. We have been discussing of late changing the safety lines as the plastic covering has become yellowed. They do clean up well with a cream cleaner and soft scrubbing pad but I think they need to be changed.
Thank you. Yes the coverings will ususally clean up well. It is what is underneath that matters though. It really depends on their age, use and where the boat has been kept. If they are more than 10-15 years old then more than likely it is time to consider new lifelines. Thanks for the read and for the comment.
I have s/s 1×19 14mm (thick…) vinyl coated shrouds on my catamaran.
Would it be advisable to take off the covers and expose the shrouds to visible check?
Hi and thank you for the question. It could be a good idea. BUT, In my experience it is only the uppers on a catamaran that have these plastic chafe sleeves. Is this the case with yours as well or do all of the shrouds have this covering. The next question is how old is the rigging and how much has it been used. I have found that in most cases it is unnecessary to remove the covering, but rather replace the standing rigging altogether if it is suspect. The plastic coverings are then typically inspected and re-used if feasible.
T.R.C.
I am presently using 3/16 SS on a Nautical Structure dingy boom and am thinking about replacing with synthetic instead of wire rope. Any concerns/reservations?
Thanks for asking…..just make sure that leads are fair and that there are no sharp edges and it should work well……