The first thing all tubers need to know is the number one cause of serious accidents are from tow ropes breaking. The governing body of the water sports industry (W.S.I.A.) has taken this matter seriously and has done extensive testing and standardization to come up with recommended tensile strengths.
Recommended Tensile Strengths.
3 person or less - 3,350 lb. break strength
4 person or less - 4,100 lb. break strength
6 person or less - 6,000 lb. break strength
Don't buy just any rope.
Many consumers simply go to their local hardware store to pick up 60 feet of polypropylene rope. It's the same material right? WRONG! The material may be similar, but those types of polypro we has twisted construction with a only a tensile strength of 1,350 lbs. for 3/8" and 2,400 lbs. for 9/16".
Compare that with tube tow ropes of the same sizes with a strength of 2,375 lbs. for 3/8" and 4,175 lbs. for 9/16". As you can see, the difference in construction makes quite an impact on the performance. Add to the fact the tow ropes have pre-spliced eyes in them. If you purchase just standard rope you will have to tie a knot in it and knots will further reduce the strength of the line by up to 50 percent.
I already have a water ski rope. Why can't I just use that?
Ski ropes are made to take consistent loads. Tube ropes are made to take shock loading when the tube line goes completely slack and then quickly taught again. Not to mention many water ski tow ropes have a handle that cannot be removed.
For more information to tubes visit Skitube.com, the towable water sport specialists.