SSYC Slip Preparation: Dockline Basics

Being a member of a yacht club has added a lot of value to my boat ownership experience. Especially when I was new to sailing, having a group of experienced boaters around to help work through issues that came up while owning a boat has been invaluable. Club members have suggested cool places to cruise to (or avoid), helped with diagnosing mechanical issues, and provided excellent recommendations on local boatyards and marine professionals.

I’m a member of South Shore Yacht Club in Milwaukee, an active, busy, and social club a mere 10 minute walk from where I live. Keeping the boat close to my home means I can sail a lot in the summer! Lots of things about SSYC are good, though the docks at their marina present a bit of a challenge to safely tie to for an entire season.

Some of these challenges have led to me making a few costly mistakes, especially in my first few years as a member. My “SSYC Slip Preparation” posts are written especially for newer SSYC members keeping their boats in a slip at SSYC, and I hope they can learn from my mistakes. And as always, my advice is merely one way of doing things… as it seems with all things boating, there are many right ways of getting the job done.

In this post, I’ll talk about weather challenges, basic objectives, and minimizing the effects of water level changes. I have a few more upcoming posts in this series:

Weather Challenges

After many beautiful, calm summer days it can be hard to believe things can get very different in the spring and fall. The lack of any tides on the Great Lakes can also lull one into getting lazy about dock lines (I did). Before mid June and after Labor Day some significant weather events can occur that affect the well being of boats tied up at SSYC.

When winds are over 20-25 knots from northeast through southeast for more than half a day or so, large waves can hit the outer rock breakwall and then seem to continue on as a swell through the marina. These swells result in a constant back and forth motion on boats and docklines. This motion can cause so much chafe that a poorly routed or unprotected dockline can wear completely through and break in just a few hours.

While there aren’t tides on the Great Lakes, water levels can change quickly in only a few minutes due to a seiche. A seiche is when water levels change on one side of the lake due to wind, and can slosh back and forth from shore to shore even to parts of the lake where the winds are calm. I’ve seen water levels increase by over 6 inches in a few minutes during a seiche… add swells on top of a seiche, and properly tying up a boat to fixed docks, like at SSYC, gets very challenging.

A broken or poorly adjusted dockline can result in lots of damage to a boat. Every year it seems a few boats get dinged up during a storm. When I owned my first boat, I initially was a little lax about properly setting up my docklines. One morning, the water level changed significantly during a gale, resulting in my boat getting too close to the finger pier. During the boat’s rocking back and forth, a lifeline stanchion got caught under the finger pier. As my boat rocked back the other way, the stanchion was ripped off the boat, bending two more stanchions before breaking the lifelines completely. It took weeks, a bunch of money, and some missed sailing days to make repairs. Ouch!

With a little preparation, damage can be safely avoided, however. Priorities barely fits in her slip on F dock, with only about 24 inches of space on either side combined with some awkward angles to deal with. But I like the slip I’m in for a bunch of reasons (close to the parking lot, the bathrooms, and bar, among others), and the marina is very close to home, so it’s in my interest to engineer a way to overcome these obstacles. Also, since club regulations allow me to keep the same slip for many consecutive seasons, it’s worth it for me to invest a bunch of time (and money) getting things just right.

Tight fit, but there’s still some space between the fenders and the hull

Basic Objectives

When setting up docklines anywhere (at SSYC or at a transient dock), I always try to consider how the boat will move when winds increase and/or change direction. After making my lines fast, I occasionally test everything by carefully running the engine in forward and reverse with different rudder inputs. If the boat gets too close to the dock during this test, or if a fender gets out of position, I make appropriate adjustments.

I try to keep Priorities far enough from the dock so that the hull doesn’t normally contact the fenders hanging from the finger pier, especially at my home dock. This minimizes the continuous scraping that quickly wears through the wax on topsides I spent so much time applying before launch! It also means that as lines stretch, the fenders and fender boards don’t bear all the force of the boat in a storm.

That being said, I still need the boat close enough to the finger pier to permit safe boarding by me, including during a storm. With all the preparation I do to have my docklines ready for a storm, it’s still nice to be able to safely board the boat to make last minute adjustments to lines and fenders during challenging conditions. Having a separate line to move the boat closer to the finger pier during nice weather, especially when boarding less nimble crew, is something I do as well.

I’ve seen some members add steps to their dock setup to facilitate easier boarding… a cool idea. Be careful that the step isn’t something that can cause damage if the boat shifts into it during docking or a storm. The best ones I’ve seen fold into the finger pier in a way that keeps them totally clear of the slip except when in use.

Minimizing the Effects of Water Level Changes

With fixed docks, it helps to initially lead docklines as horizontally as possible from boat to dock or piling. Any subsequent changes in water level up or down effectively shortens (or tightens) a dock line that was initially led horizontally. Long runs from dock to boat minimize changes to a dockline’s effective length when water levels change, and this is why long spring lines can be very effective in dealing with changing water levels. Short dock lines that slope a bunch from horizontal can have issues, and this is where I first ran into trouble.

I had the damage to my first boat because a stern line wasn’t oriented well at all. When tying my stern line to the center piling, I initially made the mistake of attaching to a loop on the top of the piling, since that seemed the only logical attachment point. Tying to the top of the piling resulted in a steep angle down from the top of the piling to my boat… far from horizontal. Lots of boaters at SSYC do this, but you can only safely get away with this if you have plenty of extra room on both sides of your boat as it sits at the dock. I also didn’t have any spring lines at all from the piling to the boat, so I was betting the well being of my boat on just this one dockline.

My first boat in the same slip. Originally, I only tied to the piling with the single, steeply sloped, upper stern line. The double horizontal line to the piling, visible in this photo, was only added AFTER the boat was damaged. Note the low water level in 2010… the tops of the lifelines are lower than the finger pier!

A dock line that steeply slopes down to the boat presents a problem: as the water level rises, such as can occur during storm conditions, the boat will end up farther from the dock/piling its attached to. This is how my first boat got its stanchions ripped off… the water level rose 8 inches in a storm, and the dock line (tied to the top of the piling) allowed my boat to end up way too close to the finger pier in big waves.

If a short dock line has a steep slope to it… such as the lower yellow arrow… the boat can get farther away from the attachment point as water level rises

Lines that angle up to the boat (i.e., attached to the dock below the boat’s cleats) are problematic, too, in that they can get too tight. This is pretty rare, especially on sailboats, since few boats’ cleats are very tall relative to the dock height at SSYC.

I try to keep my long spring lines as tight as practical

There are solutions, however. It would be nice if we could find an attachment point on the dock that is nearly the same height as the cleat on the boat, but this is easier said than done a lot of times. An alternative is to orient dock lines with a longer lead, such as with long spring lines that are kept tight, resulting in an effectively flatter orientation that isn’t as affected by changes in water levels. In some orientations, a longer lead can be found by leading docklines across each other to a cleat on the farthest side of the boat as well.

With the center piling, I tie around the piling in a way that allows the stern line to slide up and down the piling as water levels change. Many members use a large diameter drain pipe that slides over the piling, reducing any chafe that the abrasive, rusty metal piling may cause to rope dock lines, and then splice a giant eye that loops over the entire piling… this works well. The piling at my slip has rings on the side (and might be the only SSYC slip with this issue), which unfortunately prevents easy installation of any pipe over the piling. Instead I use mooring chain wrapped around the piling, which I then attach docklines to. The chain also has a small line that goes to the loop on top of the piling, but its only purpose is to prevent the mooring chain wrap from falling to the bottom when I untie the boat (I almost forgot this the first time!).

My current center piling attachments

Of course, if this chain gets between the topsides of the boat and the piling during docking and the boat rubs the piling, it will make a horrible scrape in the gelcoat (believe me, I know!). After 9 years, I’m still considering engineering a better way to protect the boat from this chain… right now I use a series of small fenders that wrap the piling. I’m also diligent about adjusting the chain to be just higher than the toerail prior to departure.

On Priorities, I try to keep both forward and aft spring lines as tight as practical. Not only does this mitigate the effects of changing water levels, it helps mitigate damage risks if a stern line fails.

Conclusion and Disclaimer

Some members avoid the worst of the storm season altogether by launching late and hauling early. This lessens the utility of their boat… though they can argue that the weather isn’t as warm anyway, so they aren’t really missing out on much of the season. I especially love sailing in September and October, though… the water is still warm and there’s plenty of wind!

I think the best advice that I can give is to ask for help from other boaters, and check out some of the methods they’ve used for tying up (good and bad). One thing I love about SSYC is how friendly everyone is. Most of us at SSYC really want to help other boaters, especially the newbies.

As I write this I have about 9 years experience as a boat owner and SSYC slip holder. I’ve learned a lot about boat ownership through the internet, and putting much of what I’ve learned back into internet content once again is one of my goals of writing My Sailing Fix. That being said, I’m not a marine professional, don’t have any marine certifications, nor am I serving in any official capacity at the yacht club, so take my advice with a grain of salt (or, perhaps, a “drop of freshwater lake?”). There are many ways to safely secure a boat in a slip. I’m just an amateur…

Questions for me? Go to my Contact Me page.

I make my own docklines from bulk rope, including splicing them myself. In my next post in this series I’ll talk about making my own docklines, keeping docklines secure but adjustable, and preventing chafe. I have a few more upcoming posts in this series, too, including:

  • Fender Boards and Bow Line Hooks
  • Shorthanded Docking Equipment

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