Tools of the Trade

This section of the module is adapted from Dana Morse’s Tools of the Trade.

In many ways, marine aquaculturists are an interesting mix of farmer and fisherman, and both farming and fishing require plenty of knowledge and a set of generic or specialized skills and tools to get various jobs done. This section reviews some of those likely tools that beginning farmers will need, and one skill in particular – that of tying good knots.  

Knots

While the old adage of “if you can’t tie a knot, tie a lot” might get you through in a pinch, it is probably not the most efficient or the safest way to secure a line. Knowing the right knot to use in a given situation is time-saving and it helps prevent danger to people, equipment and the crop. In some cases it may be as important to be able to untie the knot as it is to tie it in the first place. Having a small handful of knots that you can tie and untie quickly and correctly is an indispensable skill, and like most skills, it requires practice. The first few times might be challenging, but practice makes perfect and once you have mastered the basics, it will be easier to pick up new knots as you need them. 

According to the definitive text, Ashley’s Book of Knots, there are four classes of knots: hitches, bends, splices, and knots.  

• A hitch makes a rope fast to another object. 
• A bend unites two rope ends.
• A splice is a multi-strand bend.

A knot refers generically to knobs and loops, and to anything not included in the classes above.

The following is a list of commonly-needed knots on marine aquaculture farms, intended to get you through most situations. Some description is given, but check books, online resources, or knowledgeable individuals, to learn which knots to use and when. When practicing knot-typing, it is useful to have two lengths of manageable rope handy (two colors will help you see the knot in better perspective).

• Overhand knot – primarily used as the basis for other knots or as a stopper knot at the end of a line.
• Square knot – a quick knot that is best used for ropes of equal thickness (not to be confused with the granny knot!).
• Bowline – perhaps the most essential knot, it will not slip and is easily broken.
• Sheet Bend – An excellent alternative to the bowline, used to secure two ropes of unequal size and often used to tie into a mooring.
• Double Sheet Bend – A more secure version of the sheet bend. Best when ropes are of very unequal size.
• Cleat hitch – Tied around a horn cleat to secure a boat to a dock or float.
• Rolling Hitch – Used to secure a rope around something – most effective under strain as it will not slip but is easily undone.
• Clove Hitch – used to snuggly secure a rope around a rail, pole, or ring.
• Splice – used to join two pieces of rope together or to finish off the end of a single line.

There are many types of line used on the water: braided, twisted, and specialized lines designed for different conditions. Because each behaves differently, choosing the right line for your farm requires paying attention to a few key characteristics:

• Buoyancy – lines will either float on the surface of the water or sink to the bottom.
• Color – colorful floating lines are easily seen by boaters and can be useful in heavy traffic areas. In other circumstances it may be best to blend in to the surroundings with darker lines
• Stretch and Strain – Certain types of line are stronger and have more elasticity than others. Both factors should be considered prior to use
• Degradation – Lines weather at different rates when consistently exposed to UV and moisture

Below are four of the most frequently used lines on a farm:

• Polyester: This is the most common type of rope (also known as Terylene or Dacron). It is a sinking rope that is rot and UV-resistant. On the farm, it is a multi-purpose line and is often used to secure boats and gear, set small moorings, and sink mooring lines at the end of the season. 
• Polypropylene: This line floats and is slightly more elastic than polyester line. Once stretched, it does not return to its original length. It degrades over time with exposure to UV light. It is often used to secure floating nursery systems as it floats and is easily visible.
• Nylon: Nylon line is UV and rot-resistant. It is strong but highly elastic and can absorb a tremendous amount of energy. Because of its elasticity, the line breaks with considerable snapback and should not be used under extreme tension. 
• Kevlar: This line has no stretch and is known to be stronger than steel. It is likely stronger than needed in the farm setting.

Storing Line

Lines are best stored in coils (laying it up in circles that lie flat on top of each other). The ends of lines should be burned with the fibers melted together to avoid fraying. If burning is not possible, short-term solutions can be achieved by wrapping the end of the line in electrical tape or tying an overhand knot in the end of the line.