The 5 Minute Dockline

Ahh, the three-strand splice.  To some it's a straightforward exercise but to most it's an esoteric gordian mess best left to old salts, professional riggers, or perhaps nimble fingered children in whatever third world country the big box chandleries order their pre-made lines from.  In truth it is no more difficult to tie than a bowline, especially once you have properly started it.  Illustrated here is a quick and dirty tapered three-strand splice tied in 3/8" nylon.  On a modern boat this is best situated to a dockline and once mastered, it can be tied and finished in less than five minutes.  This is done with no tools save for a roll of tape and a pair of scissors (or a knife but I personally prefer scissors for most rope work).  The method of starting shown isn't the easiest but it's more common than my preferred method.  I'll post a follow up showing the easier method.

One last note on docklines in general, there are a couple of rules of thumb for making them.  Line diameter is scaled from the existing cleats.  You want one sixteenth of line diameter for each inch of cleat so a six inch cleat takes 3/8" line.  For length figure 1 to 1 1/2 times the length of the boat for a spring line and 1/2 to 1 times the length of the boat for a bow and stern line.

The line is prepped and ready for splicing.  The end I am splicing is laid up to the the left of the standing part of the line.  The first strand you will tuck is number 1 and it will pass under strand A.  These are the two strands on the inside of the bight so when laid out as pictured they are the two strands closest to each other.  Each strand gets tucked against the lay or in this orientation from right to left working away from the eye.

Here I have strand 1 passed under strand A against the lay.  This is one "tuck".  Next we will be tucking strand 3 which is the furthest strand to the left in the layout above (the first strand to clockwise of 1) which will be going across one and under C which is the first strand to clockwise of strand A (where your first tuck is located).  In the picture above you can just make out strand B which is where #2 will end up.

Here we are seeing strand number 3 tucked under C and being run home.  Draw up each strand carefully and completely after tucking.

The whole assembly is turned over and the final strand, #2, is tucked under B once more against the lay.  Each strand has had one full tuck.  After this we follow and over one, under one pattern always working one strand at a time and against the lay.

Two complete set of tucks are shown.  Make sure to carefully work each strand to even tension before proceeding to the next.  In nylon line we will need five complete rows of tucks to achieve maximum strength.

Here all five rows of tucks are done.  Everything looks nice and even so we're ready for the taper.  Each strand should be even in size, direction, and tension.  IF IT IS NOT RIGHT, REDO IT! Three strand line is inexpensive enough to not be too dear to cut.  Do not trust the safety of your boat or your neighbors boat to a poorly made splice.
In the above photo we are done with strand one.  Strand two and three will each get an additional tuck and finally strand three will get one last tuck.  That makes each strand exit the same side of the line and produces a nice taper.

Strand two has its extra tuck.  Note that it is now in line with strand one.  Just one more to go!

Number three has made two extra tucks and now all three strands exit the same side, each in line with each other.

Each strand is now cut off about a strand diameter away from where it exits.  In an ideal world this would be a cut with a hot knife but it's not necessary.  We'll be finishing this one with a parceling of chafe tape which is sort of like an extra tough electrical tape.  It's not the prettiest but it's quick and clean.

And here is the final splice.  All of the masking tape was removed and the taper has been taped down to clean it up.  It takes a minute and a half or so to prep the line to the point pictured in the first picture and then about three and a half minutes from there to get to the final splice so it truly is a five minute eye.