Spearfishing Fins 101 — Plastic, Fiberglass, or Carbon

Before looking for the best brand of spearfishing fins, you need to know the fin features you should look for when hunting underwater. 

spearfishing fins
Fins that let you go deeper in your hunt. Source: dan fruhauf

Here is your basic fin information to help you choose the best set of fins. 

To complete your spearfishing gear, check out our guide on the best fins: The Best Spearfishing Fins for Deep Water Spearfishing

Listen to More Spearfishing Tips on the Cast & Spear Podcast

Basic Fin Information 


With fins, there are essentially three kinds of materials to choose from. The first are those made from plastic. They are typically the most common because of their affordability. However, aggressive diving will put these types to shame as they do not perform up to par with the other types.

Fiberglass fins sit between plastics and carbons. Fiberglass will give more pop than plastics but not as much as carbons. They will be a little heavier than carbons and, depending on the manufacturer, will be roughly the same in terms of durability. They will be cheaper than carbons, which puts them in a good spot for those looking to upgrade from plastics but can’t shell out the money for carbons.

Carbons are the higher-end dive fins. Depending on the manufacturer, the responsiveness can vary between the different models. They will have the best energy transfer as well. Their price is the part that hurts more beginner spearos, so stick with plastic or fiberglass until you start diving in heavy ocean currents or know how a bit better what you’re looking for with your gear.

Fin Stiffness

Fins come in a spectrum of stiffnesses from extra soft to hard.

The hardness of your fins influences your performance in the water. The less the fin’s hardness, the easier it is to kick, as there is less resistance. If you’re a heavier person, you’ll need stiffer fins for better energy transfer for thrust. However, if you have too stiff of fins and you don’t need the stiffness, then you’ll just be wasting energy.

Foot Pocket

A foot pocket is a space on the fin where the foot settles. If the blades of your fins have an interchangeable design, chances are, so do its pockets. This feature allows the comfortable performance of your fins without you having to buy a new pair. 

Some pockets allow the fins to reach your heel, which will give you better energy transfer. Some also float, making it easier to stay horizontal while you’re breathing up.


Some spearos like to freedive the line as training. There are certain fins that allow for better cross-over between the two activities. If you plan to do freediving, look for a longer blade that will help you conserve your energy while kicking. Check out our list of best freediving fins to help you find the best pair.

What To Look For In Spearfishing Fins 


When spearfishing, you want to use a long blade rather than stubby scuba-style fins to give you more efficiency with each kick, allowing you to save more oxygen and energy for your hunt.

The extra length in the blade will help you dive deeper as it enables you to deliver more returns for each of your kicks. Unlike the fins you use for a scuba dive or snorkel, which are typically much shorter, spearfishing fins require more area to help propel you into the water. 

Foot Pocket

Your fin’s full foot pocket is designed to give you the most efficient way to get that energy from your foot to your fin’s tip.

Ensuring that the foot pocket has a perfect and comfortable fit as a loose one will let you expend more energy into kicking it hard, and a tight one will cramp your feet. Non-removable foot pockets don’t allow you to upgrade the blade without changing the whole fin. 


When purchasing the right fins or gear, it all comes down to your preference at the end of the day while taking into account the basic rule and the type of dive you’re going to be doing.

Essentially, if you weigh around 165 lbs or less, you can use a softer fin for spearfishing. If you weigh 165 to 200 lbs, you want to use a medium stiffness to provide you with a bit more material weight to work with.

If you weigh more, you can use the fins on the stiffer end to give your strong legs the weight to help propel you into the water. When spearfishing in the water where there are many currents, opt for medium stiffness to take you deeper into your dive.

Listen to More Spearfishing Tips on the Cast & Spear Podcast

Plastic Fins Vs. Carbon Fins

Plastic fins lean more on the lower price while being super durable and beginner-friendly. With plastic fins being durable, they have the disadvantage of being heavier, tiring your legs more on your dive. 

Carbon fins are lighter and more reactive than plastics, allowing you to conserve more energy and oxygen while still going deeper. These fins tend to be more expensive compared to plastic. 

When in doubt, just remember that a lot of great spearos started with plastic fins and still use them for shore-diving lobster when they don’t want to damage their nicer fins.

Jon Stenstrom
Founder & Angler
Jon Stenstrom is a fishing enthusiast. He has over 25 years of fishing experience, and 6 years of spearfishing experience, and is currently learning how to boat. Jon has his Open Water PADI Certification and FII Freediver Level 1 Certification. Jon has traveled the world to fish and dive, most notably in the Great Barrier Reef, Baja Mexico, Thailand, and Malaysia. More Articles
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