Boats are great and mysterious things. Even small boats are hard to move upon land. Once in the water, however, even a toddler can give the largest one a push that will move her. But how do we stop them when we want to dock? The spring line is the answer.
A friend of mine is getting into boating again. This post comes from a conversation the two of us had. I thought it might be helpful for others, too.
I’m no longer sure where I picked up this tip. I know it didn’t originate with me. I’m not even sure who taught this to me. But I am aware of how many people don’t understand this (which I’ll get into below) and so I thought it important to pass this along.
First, we will label the parts.
In my first diagram, we show a boat docked. This is a typical configuration around here. I know that in other places of the world the docks (pontoons) may be configured differently, but the principles will remain the same.
We will start with an overview. At our marina, there are two “main” docks that connect to one another. These are not labeled. Off these main docks are minor docks that have letter configurations: A, B, C, etc.. Off these minor docks are fingers that are numbered. This gives the slip “addresses”: C-20, E-3, etc. That is what I have shown in the picture.
Most boats (during the summer months) are moored with their bows facing the minor/letter docks. Docked this way gives a bit more privacy in the cockpit. During the winter/storm season, some of the boats have turned themselves around so their bows face into the direction of the strongest winds. Our pictured boat is in summer configuration.
1 and 1 are the two bow lines, 2 and 3 are the spring lines, and 4 is the stern line. We will be focusing on line 3 (the aft spring line), its attachment point midships on the boat (usually a cleat) and the cleat on the dock labeled 4. The arrows point to these points.
Something to think about
Ideally, you want the mid-ship fair-lead to be in a direct line to the forces involved in pushing the boat sidewise.
Say we want to move the red boat to where the yellow boat is. To make it more challenging, we only have one line to move it. Where would it need to be attached so that the red boat would move sidewise, parallel to the dock?
The reality is that currents, wind, etc. act upon the boat, too. But the closer we can get to this location the better the below approach works.
Not all keels are shaped the same, so if you are going to add a mid-ship location, it might be worth playing around a little to see what works best. Then you can add holes in your boat. 😊 For fin keel sailboats, the best place to try first is right about where the sheet winch is located.
Approaching the Dock
Now that we have labeled everything at the dock, we will move onto how to bring our red boat into her slip. Note that this will work either direction (i.e., here we are tying up to the Starboard side, but the same will work on a Port-side tie).
First, we will want to get our lines and bumpers ready. Are we going to need a boat hook? Have we talked through Plan A and if that doesn’t work, Plan B? Does everyone know what they are going to do? Have all questions been answered?
A side note:
I have seen too many (often male) captains get irate with the crew (often the female spouse/partner) when things don’t go to plan and start to yell. Do not do this. Instead, take responsibility. It is always best to talk though things before each maneuver (or sets of maneuvers).
Back to our Approach
Our goal is to use a long aft spring line to help stop the boat by cleating it to the after most cleat on the finger dock (cleat number 4 above).
To do so, we attach a line (we use a longer one than normal) to our mid-ship cleat and out the fair-lead to use as a spring line. Once we’ve stopped the boat, we can use the other lines to control and move the boat where we want her before tying everything off and putting the boat away.
This photo shows the spring line in action.
A word about the forces involved.
This next photo shows some arrows representing vectors. The vectors are just the direction of the forces.
One of the vectors is forward momentum.
One is the force of the spring line tied to the dock.
These two forces working together mean that the boat is going to travel in the direction of the double arrows (roughly). The true direction will depend upon the spring/give in the spring line and the speed of the boat, but our red boat will move snugly into the dock.
We will want to be moving as slowly as we can, while remaining in control of the boat. Ideally, we are also close enough that someone can step (not leap!) off the boat, onto the dock and have time to cleat the spring line off.
A wrap (a full turn around the horns of the cleat) is actually all that is needed. The rest of the line can be held in the hand to help adjust things as needed.
The important thing is that the boat come gently to rest against the dock (protected by the bumpers) and then the other lines (and the boat) can be adjusted as needed until everyone is satisfied.
Handing the Line to Bystanders
Be very clear what you want them to do. Too often, I have seen bystanders want to help, and grab a bow line, only to pull it towards them. The result is shown in these two photos. The bow moves toward the dock, the stern toward the neighboring boat, and the drift of our red boat is upset.
If you want to use a bystander, tell the person exactly what you want them to do with the spring line.
A few other tricks
I have not used either of these methods, but I think they are worth thinking about. Maybe they will work in your situation.
Using the sheet winch
This first one would seem to make sense if you don’t have a mid-ship cleat on your sailboat. I have heard of people running the spring line out through the mid-ship fair-lead (maybe a block attached to the toe rail?) to be cleated off on the dock.
Rather than using a cleat on the boat end of the line, the spring line ends at the sheet winch.
Once the line is cleated off on the dock, the person at the helm can use the winch (a strong attachment point) to move/control the boat from the boat.
Making a docking spring line
While out cruising one year, we met a fellow who used to moor his boat in our marina. As he often single hands, he made up a docking spring line similar to what I have pictured here.
The long loop is inside a cut garden hose to keep it open. The garden hose is still flexible enough to close but keeps the loop open when tossed.
He had the marina change the dock cleat (number 4) for a bollard.
He measured from the bollard (with the hose line on it) through the mid-ship deck fair-lead and to his cleat. Once he knew this position, he tied the smaller loop into the line. This goes through the feet of the cleat and around the horns. This way he always knew exactly where the line needed to attach to the boat.
When docking, he only had to worry about getting close enough (“Lining the boat up with the end of the dock was always easy enough”) to toss the hosed end of the line over the bollard. The spring line would pull the boat into the dock without overshooting the space left, and he could step off and tie up.
In conclusion
I hope this helps to see how a spring line can be used to stop yourself at the dock. Now you can use it yourself, and the next time you find yourself a bystander you know which line to ask for, and where to attach it.
Blessed be.