DOCKLINES AND DOCKING

Piloting a boat is only part of the activity.  Securing your boat is just as, if not more, important.

[important - The ideas contained within are those of the author.  No warranty is expressed or implied.   It is expected the reader has a working knowledge of boats, lines, and docking and obtains first hand expert opinions and guidance at the dock to ensure their safety and the proper use of all marine equipment and accessories.  Consult your marina owner, local Power Squadron, or United States Coast Guard for answers to any questions you may have.]

NEW!  I added some graphics from a pamphlet I found.  Click here to be taken to the bottom of the page for Tying off to a Piling!

                 I can hear it across the bays and rivers loud and clear, ‘I search out and find the Novice Boater Resources and what do you have for me, discussion of docklines!?  Boating is big block, testosterone inducing, wind in your hair, bikini clad babe fun!  And you give us “docklines” for reading material?”

Well, yes.  Although not the most glamorous facet of boating, it is easily one of the first trials the new boater will encounter.  From simply acquiring the needed lines and their proper placement and protection to using spring lines in docking situations; these are the nitty-gritty realities of boating.  Its right up there with cleaning creosote stained fenders and the wash down at the end of each day out.  In this section we’ll go over some of the basics of acquiring and placing docklines.  In upcoming installments we’ll actually put docklines and spring lines to use when docking at your slip or the fuel dock.

                 Docklines are the cords that keep your boat from sailing away without you while you are taking a walk ashore.  These same lines keep your boat from pounding itself to pieces at the slip when the weather gets rough or an unthinking passer-by sends a large wake your way.  Choosing the correct size, number, and material are the first steps to properly securing your boat for its safety, and yours.

 Selection

                 Docklines can be made of the same materials other lines and ropes are made of.  Nylon, cotton, and polypropylene are the most common fibers you’ll find at the local marine store.  Bigger lines used by the heavies are also commonly hemp based.  By far, exotic fibers aside, the best choice for pleasure boating docklines is nylon.  Its resistance to chaffing, strength, stretch, and ability to avoid deterioration when stored wet make nylon ideal. 

Line construction can be broken into two groups: Laid and Braided.  Laid lines are sometimes also called three-strand lines as they are made up of three lines twisted to create a single line.  This process creates a strong line that is resistant to chaffing and provides suitable strength.  Kinking can make these lines difficult to handle and coil.  These lines are economical and ubiquitous.  Braided lines consist of many small fibers braided into a single line.  These lines resist kinking, chaffing, are easy to handle, and make for a very strong line.  High end lines will often use a co-axial build process where and inner braided strength line is sheathed within a chaff resistant outer braided line. 

After material selection, the next consideration is size.  Common diameters for docklines are 3/8” (9.5 mm), ½” (12.7 mm), 5/8” (16 mm) and ¾” (19 mm).  The following table gives you an idea of the line diameter that may be best for your boat (all else being equal).  Don’t forget, larger line diameter makes it easier on your hands and will last longer.  On the other hand, you don’t want a diameter so thick it can’t get a few good turns around the cleats on your boat. 

Table 1

Dock line Size and Length 

                In general, you should count on getting six docklines.  If you live in an area of moderate tides, the length of your boat or 2/3 the length of your boat is a good rule of thumb for selecting the length of your lines. If you live in an area of wide tidal ranges, 1.5 times to twice the length of your boat is more appropriate.  If you keep your boat in a slip you really need two sets of docklines.  The docklines and taught-lines for your slip are often one of those hidden costs you don’t count on as they are not normally provided by the marina.  As we’ll see later, once you get your docklines set, you won’t be removing them.  You’ll keep your second set of lines for when you travel to other marinas or need that unexpected tow if something goes wrong out on the water. 

                Special note:  If you haven’t noticed yet, boaters tend to be a bit flashy with their boats.  If you travel to another marina you will want your boat to look as trim and sharp as possible.  Would you use diaper white docklines on with your gold trim boat?  Of course not!  Consider getting a set of generic white thick lines for your home slip and a set of color lines, matching your boats trim or color theme of course, for your travel lines.  A set of black lines on a gold trimmed boat can make a real sharp combination.  Not to mention colored lines can hide the chaffs stains better than white making your boat look that much more dapper. 

Placement 

                Now that you are a few dollars lighter, but better equipped, it is time to outfit your slip with your lines.  If you trailer your boat, take notes for when you decide to travel to another marina or have to tie off for a period of time at the boat ramp.  Figures A and B below show two common configurations for tying off your boat.  The purpose of the docklines is to keep the boat from floating away and to prevent it from banging laterally into the dock and pilings.  Spring lines are lines that keep the boat from floating out of the slip or traveling along the boats long axis.   The idealized layout in Figure A below may be more useful for your longterm slip location.  This configuration uses two lines of the bow and stern to maintain it in the center of the slip and one or two spring-lines to keep it away from the dock and from nosing out.  If you can find out the direction most storms approach from, or if you hear a particularly bad storm or hurricane is approaching, you can double up on the lines that will take the most stress for extra security.  Figure B below shows a configuration used for temporary docking.  It is not as desirable for long term storage as Figure A because there is no way to keep the boat from bumping into the dock.  Even with the shown fenders, this bumping in the long term can’t be any good for your boat.  If you look in a boating catalog you can find items that can help out in this situation.  One such item is called a mooring whip.  Mooring whips are attached to your boat and act to pull the boat from the dock giving you the effect of opposite pilings.

Figure A & B

                Once you decide which layout you are going to go with, you need to attaché your docklines to the dock cleats or piling.  As these will be rather permanent, you don’t need to use easy release knots and can use as many loops or knots as you feel comfortable with AFTER get the best length played out.  The correct length is the one that will keep the boat from pounding into the pilings or dock but not so short that they will put strain on the cleats when the tide is high or low.  Figure C shows the effect of tidal swings and helps to illustrate why longer docklines are desirable for areas with wide tidal swings.  A method that may help you set your lines is to wait for dead low tide and set the lines to be sure the boat is secure and most slack is out of the lines, but the lines are not tight.  Remember that situations may arise (neap tides; low tide with winds blowing out) that create exceptionally low tides so you want to be sure your boat will not hang if these conditions come around.   Once this is done, watch the lines and position of the boat as the tides rise.  When at higher tides the lines will be looser and if too loose, bumping may be possible.  This may be unavoidable and could be a sign your slip is too small for your boat.  If this will occur, affix fender to the danger zones or to the pilings (if the marina owner will let you).  Line snubbers may help take out the slack at higher tides.

Figure C

                Once you get the lines sized up, finish them off to the pilings and dock cleats using which ever knots you are comfortable with.  This is a critical part, so make sure you get it secure and ask your marina owner to give your setup a final ok.  He or she will likely have to chase down your boat if it gets away while you are away or it starts to create a hazard to others or itself, so get a final “okay.” When you are done.  Using tape or a permanent maker, mark your line at a permanent datum point such as the dock planking or piling itself.  This way, if you ever have to take your lines down for any reason you’ll be able to reaffix them at the ideal lengths quickly.  Where lines rub against pilings or dock planks get line protectors to prevent chaffing.  Old garden hoses work great for this.  Just cut a foot or so piece off and slit it open.  Place it over the line where the rub occurs and use duct tape or another method to affix in position.  And, finally, the coup de grace…Felmish Docklines.  These are the neatly coiled docklines you see on the dock.  Neatly coil your remaining lines into these so that others walking by don’t trip or tangle themselves in your lines.  Not only do they really work, they make your work look much more ship shape and orderly.

Tying off to a Piling

Here are a few dockline tying tips I found in a pamphlet from the Virginia Marine Institute   I take no credit for any of this information.  VA Marine Institute provides surveys as well as different training programs for Captains and surveyors a like.  I know nothing of them other than that.

When learning the basics, practice them over and over again at the comfort of your home marina or dock.  Each time you go to your boat run through the basics.  This way, when you are tying up at a foreign location you won't be banging your memory for the proper way to tie a clove hitch (ie Practice Makes Perfect).

Copyright © Scott Morgan. All rights reserved.
Revised: December 14, 2000.