Life Lines and Tethers

I navigate alone quite often, so that the highest risk comes from falling overboard. Therefore, I must always, even in good weather, be attached to the boat by means of a lifeline system. There is also another requirement: long standard tethers (1.8 meters) are not a good option when sailing alone. Yes, such a tether can prevent that you would become detached from the boat, but it will not prevent you from falling overboard. And it is a well-known fact that a person who fell over the board and is attached by a tether can have very hard time getting back on boat (basically, it is virtually impossible without outside help). There were several cases where the person who fell overboard, even drowned, despite being tethered in and receiving help from other members of crew. Since my boat runs on autopilot, it would become a nightmare if you fall overboard, even tethered in. So the design of life lines and tethers had to be such as to almost preclude the possibility to fall overboard.

That implied two things: the tether had to be very short and the life lines had to run close to the center line of the boat and had to give in very little, i.e. the life line attachment points had to be rather close to each other. I decided that the two tether lines I would use would be 70 and 90 cm. long, respectively.

The first life line was inside the cockpit, and it was short, about 1 meter long. When clipped with the longer tether (90 cm.) it allowed me to move freely around the cockpit, sit near the transom so that I could operate the engine (changing gears, for instance), but it was virtually impossible to fall out of the cockpit, either to the side or to the rear.

The next and most important life lines were those which ran towards the bow from the cockpit. I decided to raise them by about 25 cm. from the top of the roof. The reason for that was to keep the tether as short as possible, and so to be able to walk upright with a 70 cm. tether you have to have the life lines about 20 cm. in the air.

So, just in front of mast I installed a short stainless post almost 30 cm. high.

The post has another function as well, it allows for a tow line to be attached to it (the post installation is quite sturdy - there are 8 bolts at the base and the post is connected by means of two stainless steel angles to the mast step. This also makes the post able to resist extreme loads in case a person falls off the boat.

The stainless steel post for tying the life lines.

There were two stainless steel square tubing pieces attached to both sides of the hatch, and a nylon flat line was attached between the tubings (with knot) and to the cleat of the center post. Note 4 through-bolts for attaching each tubing to the deck. There were cases reported when the tether line attachment point was ripped out and persons lost overboard when boats overturned. With the four bolts I have installed, one would have to rip out the entire cabin wall to dislodge them.

The square tubing with the life line attached.
The two square tubings on both sides of the hatch can be seen. By the way, I discovered that they make an excellent holding point for hands, so that one can stand steadily in rough seas, and also they help to go down into the cabin.
The life lines.

This configuration allowed me to go to the bow passing inside the shrouds and without being in danger of falling overboard. Once I am at the centerpost, I had to clip me in to U-bolt which is located on the centerline and towards the bow, and then I could unclip myself from the nylon line running towards the cockpit.

The nylon line I am using is a 2600-pound one. Possibly it should be stronger (the norm is 4000 pounds I believe), but considering that the tethers are short, there would be much less shock load from the jerk when falling, so I am OK with it. (Thicker lines are more difficult to tie down on the cleat and also the tether hook does not slide as well.

The U-bolt on the bow for the tether.