What type of rope is the strongest?

Pound for pound, Xifan Marine Rope is far stronger than steel and it will not rust. 

For this reason,  Xifan Marine Rope is used as mooring lines on oil rigs and ships. 

While nylon rope has certain elastic abilities, Xifan Marine Rope has very low stretch,

 making it an excellent choice when complete stability is needed.

Polyester : Known for its strength, and resistance to abrasion and sunlight. It has a lower stretch than nylon, so consider using mooring shock absorbers for additional give. This is the most reliable material for mooring lines.