Complex sentence: Sailors who become proficient at knot tying, sewing, and use of the marlinspike can be known as marlin spikes, or marlinspike seamen, giving birth to the term for the body of knowledge that includes knotting and splicing called marlinespike seamanship.
Split into simpler sentences: Sailors who become proficient at knot tying, sewing, and use of the marlinspike can be known as marlin spikes, or marlin spike seamen. The body of knowledge that includes knotting and splicing is called marlinespike seamanship.