Just to elaborate more on the marlin spike and constrictor knot
The knot is not advised as a bow string knot, though it will not slip readily it will not lie parallel with the limbs.
It is the perfect semi permanent knot when used for whipping, if it's done right you should need to cut it off. or take absolutely ages.
It can be used losely to temporarily to fix cordage materials to saplings.
It makes a great rope ladder knot, slips slightly less than a clove hitch.
It is easy to tie and learn being similar to the clove hitch.
It can be tied on the bight if you learn the form, this is quite tricky but well worth it, when tying up double guy lines on shelters etc.
It can make a quick emergency tie for arterial bleeding, especially if you carry one preready on your hat in strong cord. with masking tape taped edges so it doesn't loosen.
Is a great binder for spear making using knives etc, a few small ones will hold very well, reducing the need for longer lashing and longer cords, meaning you have less cord to make.
Great for the ends of longer whippings, eg storage of paracord on knife handles. thread around torches etc. Especially if you want easy access to it, unlike the common bow nocking wrap.
Marlin spike hitching and use
Marlin spike hitch, start to make a simple slip knot place the marlin spike through the loop made and pull back to tighten, can be made one handed whilst holding the spike.
Used for and especially good for tightly tying a wrap/whipping/lashing etc whilst saving the blisters on your hands from starting.
Can be used on thinner straps for compression bags to get a real good grip and shrink.
It has many more uses in splicing, rope making by preturning all strands, you can count the rotations this way
Hope this has helped some.