In construction, there is always a unique way of fastening things. In building a multi-story skyscraper, for example, there are welded stud bolts that are unique to this type of construction. The same holds true of marine construction. Here are three types of marine fasteners unique to marine construction and how these fasteners are used. 

1. Teak Bolts

Teak wood has the unique property of resisting rot. Considering that teak comes from hot, humid, tropical areas in Asia, it makes sense that these trees would, over time, develop a resistance to wet rot. It is one of the reasons why boat- and shipbuilders use teak to fabricate hulls, decks, and/or teak wood accents. It is also why teak bolts are crafted. These wood plugs resembling wine corks are entirely teak wood. They come in varying sizes, and they are used to plug drilled holes in teak construction. If you have a teak dock, for example, you would use these teak bolts to plug the areas where you have drilled screws or bolts to fasten parts of the dock together. The teak bolts keep water out and away from these metal fasteners to prevent rust and/or corrosion. 

2. Canvas Fasteners

A lot of boats use canvas tarps to keep the boats dry when the boats are docked but still exposed to the elements. One part of the fastener is pushed through and secured to the sheet of canvas, while the other part is attached to some part of your boat. Canvas fasteners may also be used to create grommets for rigging in sails for sailboats. 

3. Toggles

Stainless steel toggles are a unique marine fastener that allows you to attach a sort of "handle" to your boat onto which you can tie ropes and secure the boat to a dock, or just secure a supply of rope in the boat. The toggles are best used when you cannot secure the underside of the fastener via bolt or nut because the underside of the toggle is inserted into the deck of the boat or the edges of the prow and stern where you cannot reach into the edges without cutting out sections of fiberglass. They can never be removed once installed, so make sure you have the toggles exactly where you want to place them before you install them. Otherwise, you may have to take a special saw to your boat to cut the toggles free.