POLYPROPYLENE MESH

The most common material for trampolines is polypropylene mesh. It is similar in appearance to shade cloth, but much heavier. This material is used extensively in the recreational trampoline industry and has been successfully applied to the marine industry. This material can be readily found on nearly all beach-cats and has been used on day sailors and charter boats as large as 77'. It is an affordable and durable material with UV inhibitors to endure many years of constant exposure to sunlight. It is easy to work with, sews easily and provides a firm stiff surface when stretched. Polypro is very abrasion resistant and performance characteristics do not change when wet. Polypro has a useful weight carrying capacity of approximately 800 lbs., however when the load is uniformly distributed along the anchor points, the load may be significantly higher. Some advantages are that a tramp made from polypro is self draining, will stop a significant amount of splash and a have very low stretch factor. It is a comfortable surface to sit or walk on. Some disadvantages of polypro are high resistance to wind and wave forces. If the application will expect heavy seas or high winds that will adversely affect the handling of the boat, polypro is not recommended. 

KNITTED NET

Commonly used on production boats manufactured by Corsair Marine on F series boats, this knitted net is a polyester based material with a softer feel than polypro or open netting. It offers a higher degree of open area for less wind and water resistance than polypro mesh. It is more difficult to work with since there is a fair amount of stretch in the material. Untreated, the Knitted Net is subject to UV degradation. This material can be treated with UltraVinyl Guard coating to improve resistance to UV and abrasion. Once coated, Knitted Net will provide years of service and can be recoated as necessary. Knitted Net can be drawn tight to produce a flat smooth surface over fairly narrow spans. Advantages of Knitted Net will be a softer (folds up with retractable amas) finish, a bit "stretchier" than polypro with less wind and wave resistance. Because the material is woven, it can readily be treated for UV and abrasion. The material sews easily, and reinforced borders are easily applied. When wet, it is not as slippery as polypro. Knitted Net will have a higher degree of wave and wind resistance than open netting but less than polypro. Unsupported spans over 10' will tend to sag without reinforcement. 

OPEN NET

The classic material used for trampolines and netting. Ultimately, open net can be the strongest available material, and often it can be lashed directly to a boat without fabricating borders. Depending on the material (nylon, polyester, or Spectra) and construction (knotted or knotless) the particular netting will have a variety of performance characteristics. Unsupported, all netting will exhibit some amount of sagging (not stretch) across a span. Because open netting has relatively large spacing, it is not very comfortable to sit or walk on, but offers the ultimate in low windage and wave resistance necessary for blue water cruising. 

Nylon nets- Ideal for impact applications. Because nylon will stretch when a load is placed on it, the damage from a sudden impact (heavy falling weight for example) will be minimized. Unfortunately, when stretched taut as in a multihull trampoline application, this stretch is going to cause an adverse reaction by continuing to stretch when a load is placed on the net (walking on net), or when wetted. Excellent for safety net, but not suitable for trampoline nets. 

Polyester nets- Low stretch. Good for tramp applications for the reasons nylon is not. The netting can be stretched taut, and will exhibit a significantly lower amount of stretch when wet or loaded down. There are varieties of polyester designed for high performance applications that meet the needs of the boating community. 

Spectra nets- extremely low stretch. Almost no stretch, a very strong material where individual twines are a fraction of the size of nets of other materials. Because the twine is small, the netting can be uncomfortable to walk or sit on. This material is very expensive, and is requested only in situations where performance is the highest priority.