Marine Heaving Line FAQ's
In basic terms, what is a heaving line and how is it used?
A heaving line is a length of rope that has been configured for ease of throwing, sometimes long distances across the water. It is normally attached to, and used for sending, a much heavier line across the open distance between a vessel and a pier, or sometimes between two vessels.
The most common application is for docking. For example, whereas it may be difficult to toss a thick, 40' dockline to the fuel dock attendant on a breezy day, it is quite easy to send the heaving line in those same conditions. Once the attendant has received the end of the heaving line, he simply uses it to "pull" the heavy dockline line to himself so that it can be made off to a piling or cleat in the usual way.
Do I need a heaving line?
In the example above, the obvious alternative would be to pilot the vessel close enough to the pier so that her docklines can be handed or passed over a shorter, more manageable distance. The question of whether or not to use a heaving line is truly a matter of scale... the larger (or less maneuverable) the vessel... and/or the longer (or heavier; stiffer) her docklines... and/or the less favorable the wind and current... the safer and more prudent it becomes to stand off a bit (keep some distance from the pier) and toss a heaving line.
Which length is best?
It depends on how the heaving line will be used, as there might be several factors involved, including the anticipated need for 'range' and the size and maneuverability of the vessel itself. Generally, most small-craft and recreational vessels are maneuverable enough in close quarter docking situations, and probably won't need a heaving line at all.
The exception here would be certain medium-size (and up) sailboats, many of which are notoriously uncooperative in reverse gear. Add in a cross current on a breezy day... perhaps with a long keel or a folding propeller... and the average 30+ foot sailboat can become quite unresponsive to her engine and helm. Even so, the ability to get a 50 or 60-foot line passed off to the dock... quickly... the first time... can make all the difference between making a scene or docking like a pro.
Larger vessels and yachts will almost always benefit from a longer heaving line (100'), as will vessels that have a relatively high freeboard (height; as measured from waterline to deck). 100-feet is also a good, working length for most commercial trawlers, towboats and rescue boats.
Ships, tugs, and extra-large yachts with ample deckspace and the occasional need for maximum range will appreciate the 150' length, which also happens to be about the longest distance that a heaving line can be tossed manually... and that by a skilled deckhand with a good arm.
An important point to keep in mind is that normally a heaving line should be thrown 'past' its target (and for safety, somewhat off to the side if the target is a person!). Sometimes, the advantage of a longer heaving line is not necessarily that the full coil will be thrown; but that there will be less resistance (or snap-back) when the line has fully extended to reach its target. It's also nice to have some slack to work with.
I'm thinking about building my own heaving line. What size/type rope do you suggest?
We recommend either 1/4" or 5/16" diameter. Any smaller and there's a tendency to get tangled up. Any bigger and it just gets heavier and more difficult to throw. We also prefer 3-strand construction over braid because it has a more gradual, natural resistance to 'hockling' (tight twists and kinks) when thrown from a coil.
Of the various materials, we like polyester (Dacron) the best because it combines excellent strength and durability with consistent handling. Polypropylene is also sometimes used (hi-visibility, floating rope) but it has to be kept out of the sun, and with its lower density it doesn't "carry" as well through the air.
Keep in mind that you'll need about 12-15' of extra length, over and above the length of the finished heaving line. About 10' goes into the monkey's fist knot... and then another foot or so goes into the tapered splice (at the monkey's fist end)... and then another foot or so for the eye-splice at the bitter end.
What goes inside the Monkey's Fist knot?
It is customary to form the monkey's fist knot over a reasonably lightweight "core" which adds to the mass, diameter and aerodynamic properties (roundness) of the knot itself. But the practice of 'loading' a monkey's fist with lead shot, bolts, marbles or other similar materials should be absolutely avoided. The property damages and injuries that can be created with a "loaded" heaving line are substantial. Remember, the Monkey's Fist is often traveling the full distance of 50 to 100' at somewhat high speed...
Fortunately, a properly built heaving line doesn't rely upon the weight of its core in order to function efficiently. Quite the contrary... it's the concentrated shape and weight of the rope itself, configured as a Monkey's Fist, that overcomes inertia and enables the entire heaving line to travel through the air... with the Monkey's Fist in the lead, and the balance of the coil spreading out just behind it.
Consider this: A "5-finger" monkey's fist that is constructed of 1/4" dacron rope over a 1.75" core will require approximately 10 feet of rope, and the concentrated weight of the rope will be just over a quarter pound. On a 60-foot heaving line, the Monkey's Fist end will represent between 12-14%% of the total weight of the heaving line! Even on a 100-foot heaving line, the Monkey's Fist will represent nearly 10% of the total weight.
If we increase the line diameter to 5/16" over the same core, the finished weight will be approximately 1/3 pound. In our experience, this is more than enough for good performance in breezy, rough conditions. But if you want more weight, try the 'old-timer's' trick of dipping the monkey's fist end into the water before tossing the line...
However interesting this might be, it's only the first half of the story. The second part relates to the aerodynamics and handling characteristics of the heaving line itself.
Basically there are 2 options:
- Constructing the monkey's fist knot with just a short tail and a loop, then tying it to some other (spare) length of line whenever a heaving line is needed.
- Constructing the monkey's fist knot as an integral feature of a dedicated heaving line.
The obvious advantage of a "short tail" monkey's fist is that may be slightly less expensive, involving only 12-15 feet of rope (including the attachment loop) plus the time and/or labor to make it. Of course the theoretical cost savings assumes that we already have a suitable piece of spare line to which we can attach our short tail monkey's fist whenever we need it.
However a heaving line which is constructed as a single-purpose unit, with an integrated Monkey's Fist at the end will always offer superior performance over a separate Monkey's Fist that's tied to the end of another line. That's because the additional weight and windage of a secondary connection point is a detriment to the overall efficiency.
In other words, the aerodynamics, and balance of a monkey's fist that is spliced and tapered into the standing part of a heaving line will always be optimal because it eliminates the drag and counterweight effect of an attachment knot, like a bowline, rolling hitch, etc. It may not seem like much difference in calm conditions, but as with most things rigging related, the drag is increased exponentially as the wind picks up.