...Regarding the options, the right one is to have the jack line well inside the boat (and not normally were they are used, between cleats) and having a short double tether. On the last years, after several accidents with people dying going overboard connected to tethers, their length diminished drastically on the European market. From 1.5m average they have now about 1m, maybe just a little bit more. More difficult to use but certainly safer.
Let's talk about my specific boat for a few seconds:
There are a few challenges:
- The beam of the whole boat is only 8.5'. Your argument about 6' tether being too long almost certainly applies to my boat, and I raised this issue on the Catalina 250 website.
- There are no side decks.
- The anchor locker is easily obstructed by jacklines at the bow.
- It's a small boat, so not a lot of good spaces to put D-rings. And based on the Sail Delmarva links, I don't want to clamp directly to D-rings - I just want places to attach jacklines.
- The contour of the front cabin is not a gradual slope - more of a "windshield" type front window - so a jackline will not lie flat and will be a trip hazard.
Because of the fact that I will not take this boat offshore, and will singlehand maybe 5% of the time, I am not going to install permanent jacklines. If I did, item #5 above would make them hazardous. You must realize that everything is a compromise, and on this boat jacklines can create more hazards than they solve if you are sailing in a situation where you don't need them. So I will install temporary jacklines only if I am singlehanding.
Per the advice of people on the Catalina website, I will install the temporary jacklines from the bow cleats to the stern cleats (which you can see in the above pic). I will do one on each side. I briefly thought about wrapping each one around the mast to keep them near the centerline on the bow (and gradually sloping to the corner stern cleats), so I'd invite your suggestions about that, but that would definitely interfere with the anchor locker and the companionway. It may be better to run one down each side, where they will avoid the anchor locker and stay above the coamings in the cockpit.
I am very concerned about a 6' tether being too long, so I am faced with the dilemma of making a custom tether or buying a double 3'-6' one and using the short end wherever possible. I could also hedge my bets by clamping onto the windward jackline whenever possible, under the hypothesis that the most likely scenario of me going overboard is a wave carrying me over the leeward edge. That way I will probably be clamped to the most distant jackline before I go over. If I'm lucky I get stopped on the leeward side of the deck before I even make it over the side. In a strange way, this actually makes my boat's narrow beam and lack of side decks into an advantage, since it enables me to clamp onto the far side with an ordinary 6' jackline. I can even try clamping both the 3' and 6' ends on the high side of the boat, and only release the short one if I need the full 6' length to reach something further away.
As for the actual jackline, someone at the Catalina site suggested the below webbing (click the pic for a link), that matches the specs of West Marine's $75 jacklines. It does not have a sewn loop on one end like the WM lines, but I really don't understand the benefit of having one loop. If you need to tie the other end (which causes some loss of strength), you might as well tie both ends. And since I will cleat both off, the strength loss will only be about 15% (according to one of the Sail Delmarva links posted above). I'll also have 300' of webbing, so I can avoid UV damage by replacing it every time I sail if I want to.
By the way, if I go for this webbing, I will be selling off the excess to anyone who wants it. I really don't need to replace it every time I go sailing.