In this first part of our underwater hunting online course, we take a closer look at the harpoon.
CONSTRUCTION OF THE HARPOON
HARPUNE PROPERTIES
There is a sea of harpoons on the market with countless brands, models and variations. We started Frivannsliv over 15 years ago and since then have tried and tested a number of harpoons. In this article we share our experiences.
The most important characteristic of a harpoon is its precision. When we come across a harpoon that doesn't hit where it should, we ask ourselves the question: Why is this harpoon imprecise? Over the years, we have gained a lot of experience and we have systematically worked to uncover old and new truths. We wanted to uncover factors on the harpoon itself, but also what importance you as an underwater hunter have to the precision and range of the harpoon.
The tests are done in a swimming pool where we can reproduce the same conditions for each shot. This is how we gathered data to draw the right experiences and conclusions. The tests were carried out by three underwater hunters with extensive experience on a measured shooting range. All shots are filmed with a high-speed camera so that we can uncover what happens at the moment the shot is fired, as well as follow the arrow's path right up to the flash.
Photo: Aleksander Nordahl, ettpust.com
PART 1 - TECHNICAL SOLUTIONS AND HARPOON FACTORS
THE LENGTH OF THE HARPOON
Most harpoons come in different lengths. The most common lengths for underwater hunting in Norway are from 90 cm to 115 cm. A long harpoon gives a longer range and makes it easier to hold the harpoon steady when aiming. A short harpoon is easier to maneuver but has less power and range. Young people can start with a harpoon of 75 cm.
The longer the harpoon becomes, the more important it becomes that the harpoon tube is rigid and strong so that it does not bend when the harpoon is loaded. The length of the harpoon should be in proportion to the length of your arms (you must be able to load it) and to what power you need when hunting.
KNIT LENGTH AND DIMENSIONS
Many harpoons are supplied with one rubber band, which is usually 18 mm. There are also several models that are supplied with a 16 mm or 20 mm harpoon string.
A harpoon with one string is quick to load, but it can also be heavy, and thus uncomfortable and tiring. On newer harpoon models, it is common to have several thin bands. It makes the harpoon easy to load while providing more power. 2x16 mm harpoon knitting is a very popular and good setup that we have on most of our harpoon models.
It is also our experience that 2 x 16mm harpoon string gives a smoother power transfer and less recoil which in turn gives more comfortable shots compared to a thicker string where the shot goes off with "a bang".
The length of the elastics is also important. If the elastics are too long, you will not get enough power, if they are too short, the harpoon will be difficult to load. The quality and power of elastics can vary greatly between different manufacturers
THE HARPOON ARROW
The length of the arrow is proportional to the length of the harpoon tube. The longer the arrow you have, the stiffer it needs to be to avoid throwing. The stiffness of the arrow is affected by steel quality and/or arrow thickness. The most common thickness of arrows is 6.5 mm or 7 mm.
At the front of the arrow is the barb. It has a great influence on the trajectory of the arrow in the water. In our pool test, we found that arrows with a single barb were the most accurate.
Many years ago we hunted a lot with Riffe harpoons with 8 mm arrows with a large screw-on arrowhead. We ourselves were satisfied with this set-up as we did not discover any weaknesses with the precision during hunting. The surprise was therefore great when we tested it on blinkers in a pool, where it turned out to cause a large spread on the blinker disc. We therefore replaced the arrow with a 7 mm one with a simple barb, and we immediately got a good collection on the indicator disc.
In the pool sessions, we have really discovered the importance of the barb for the trajectory of the arrow . If the barb is up on the arrow, the arrowhead will be pushed down. If the barb is on the underside of the arrow, the arrow is lifted upwards. This is actually an advantage and not a disadvantage, but it is important to know your harpoon to know which solution is correct. Some harpoons should have the barb on the underside to prevent too low shots, other harpoons should have the barb on top of the arrow to counteract too high shots. This assessment is linked to the stiffness and material of the harpoon tube.
THE HARPOON TUBE
Most harpoons are supplied with aluminum tubes of varying quality. On more expensive harpoons, it is common to use carbon or wood, usually teak. The advantage of carbon and wood is the stiffness. A rigid harpoon tube does not bend when the harpoon is loaded, even on long harpoons with a lot of power. This prevents the arrow from throwing during the shot, and provides a tighter collection of shots on the target disc. If the harpoon tube is too soft, preferably in combination with too much force, the harpoon tube will bend. When the shot goes off, the harpoon tube will throw itself out again and throw/throw the arrow. We look more closely at arrow throwing/vibration in the next part of the article.
The design of the harpoon tube can and does have a great impact on how the harpoon behaves under water. A good harpoon must be able to be moved evenly horizontally and vertically without vibrations or unwanted movements occurring.
Read the next part - Shooting technique!
