Ropes are the direct line of attachment between a spotter, and the diver. If the coach (or individual who is the spotter) has inadequate rope, it does not matter how good the pulleys, clips, or spotting belt are, that connection will be lost. The result: an inured diver.
For use in spotting, ropes that are designed for climbing and rescue work are desireable. They can handle the load required and are made to withstand normal wear and tear.
Even when choosing among the many type of climbing and rescue ropes, a coach (or the individual purchasing the rope) should keep in mind several important considerations:
The Diameter of the Rope
Spotting rope is available in a variety of diameters, ranging from 5/16-in (9mm) to 5/8-inch (15.5mm). The thicker a rope, the stronger it will be; but the thicker the rope, the more it will weigh. So before making a choice consider where the rope will be used – over a trampoline or over the water in a pool. A thick rope that is installed over a water on three-meter springboard can be much more difficult to handle than one over a trampoline spotting rig. A good rule of thumb for spotting applications is to use a ½ inch rope for trampoline and dryland boards, but a smaller rope for water spotting due to the weight involved.
Static vs. Dynamic Rope
For spotting, the rope to choose is static. The difference between the two types is the amount of stretch that occurs when force is applied to the rope. Dynamic ropes, which are primarily used for sport climbing and rescue work, have the ability to stretch when force is applied. When the rope stretches, it lessens the impact on the individual to whom the rope is attached, but it also reduces the amount of force that the rope can then handle in subsequent uses.
As an example, If a climber falls on a mountain and is attached to a dynamic rope, it’s ability to stretch will lessen the impact on the climber and will reduce the likelihood of injury. That same rope will probably not be used over a long period of time because it will not be as strong as was before the climber fell. If that same type of rope is used in spotting, the amount of weight it can support is reduced each time a force is applied. If you use a dynamic rope every day for spotting, it will not be long before that rope is useless for spotting applications.
Static rope will not stretch to the extent of a dynamic rope, and can be used on a regular basis without losing its ability to withstand the force to which it is subjected. A static rope is much safer, and practical for spotting.
Nylon vs Polyester
Nylon and polyester are the two most common materials used to make rescue and climbing ropes, but should your rope be nylon, polyester, or a combination. The biggest concern here is how much your rope is exposed to water. If your dryland setting is - as the name applies, “dry,” nylon rope is acceptable, although a combination is probably best.
Nylon rope is hydrophilic – which means that it absorbs water. When a rope absorbs water, it’s ability to stretch and change and use the properties for which it was constructed, will change. The less a rope changes in spotting, the better.
Polyesther rope is hydrophobic – which means that it is not effected by water. If your spotting rope will be exposed to water then it is best to choose a polyester rope, or one that is a blend containing more polyester than nylon. Polyester is not as strong as nylon, but as mentioned earlier, will not stretch as easily.
Many rope companies have their own proprietary technology that will allow the rope to be unaffected when immersed in water. This can be an important attribute when choosing a rope. Additionally, many of these same companies have products that will both clean and assist the rope in repelling water and moisture. For both the safety and longevity of your rope, clean and apply one of these products on a regular basis.