There is an infinite amount of knots out there, with a knot for every situation in sailing, camping, climbing and of course fishing. However, in sea fishing anglers can get by knowing relatively few knots. Of course, some older anglers pride themselves on knowing a massive number of different knots, but the reality is that most modern rigs will be made using very few knots. The uni knot is an adaptable and small yet strong knot which can be used to tie hooks, links and swivels to line. It is specifically developed to be tied with monofilament and is the main knot used in the majority of modern rigs. The shock leader/main line knot and stop knot are also based on the uni knot. While the trapped swivel method gives the best and strongest way of attaching hooklengths to a rig body the dropper knot is included here as it provides a much cheaper (although less effective) method of achieving the same thing.
Knots which are designed to be tied with rope may not work well when tied with monofilament line. The reason for this is that rope binds against itself, and knots that will bed in tight with rope risk slipping apart when tied in monofilament. The uni knot, dropper knot and mainline/leader knot (which is based on the uni knot) are all specifically designed to work with monofilament and the loops tied against loops principle means these knots will not slip apart. The half-blood knot was a popular knot years ago, and does work when tied in monofilament, but the uni knot is smaller, much stronger and easier to tie. Any angler still using a half-blood knot these days should consider switching to the uni knot. The uni knot works well with all monofilament lines up to about 80lb breaking strain. Lines stronger than this are too thick to tie safely, and large heavy duty crimps will be need to be used with line of this strength.
Also be aware that when a knot is pulled together the friction that is created can heat up the monofilament and reduce the strength of the line. For this reason it is important to lubricate the knot as it is pulled together. This can be done with a little water, although many anglers find it easier to use saliva to lubricate the knot. Also remember to try to keep knots to a minimum in any rig – no matter how well a knot is tied every one contributes to reducing the overall strength of the rig/line. Take time and care when tying knots, as many good fish are lost due to hastily and badly tied knots. Take a second to look at a knot once it is complete and if there is any doubt over it then cut the line and tie it again. Losing fish is part of fishing but no one wants to lose a decent fish because a knot they tied let them down!