The skin squeeze effect in divingWritten by Jakob Jelling
Skin squeeze is one of barotrauma problems which divers can suffer due to pressure factors involved in practice of sport. This way, a barotrauma can be caused due to differences between pressure of water and surface pressure to which diver's body is adequate and used to. Barotraumas include problems such as external, inner and middle ear squeeze, eye squeeze, skin squeeze, sinus squeeze and lung squeeze.While being into water, a diver is in a heavier environment than when he is in surface due to fact that water is a denser medium than air. The relationship between density of environment, its pressure and way it affects human body are explained through several physic laws, among which we can specifically find Boyle's law, Dalton's law and Henry's law. These physic laws explain that there is a constant relationship among volume and pressure multiplication. This way, it explains that way in which deeper a diver goes into water, more pressure he will be exposed to. Therefore, whenever they wish to go deep into water, divers should have this law in mind and take precautions necessary to avoid effects which this pressure increase can have on them.
| | Fishing the Dropper FlyWritten by Cameron Larsen
Over past decade or so, some fly fishers have hailed dropper system as latest and greatest thing to hit fly fishing since graphite fly rod. The truth is two fly dropper system has been around since fly fishing began. Like all techniques it has gone in and out of style over generations. As new technologies are developed, fly fishing trends change, some things are labeled obsolete only to experience a re-birth later on. For whatever reason dropper fly has experienced just such a re-birth and its uses are becoming more varied as well.The two fly dropper system is simply a way to fish two flies at one time, actually a fly fisher could fish more than two flies, but for this article we will stick to just two flies. The advantages of fishing two flies can be many. You can more quickly identify 'hot fly', if fish hit one fly repeatedly you can eliminate dropper fly. Another advantage is your ability to search through multiple levels in water column. The theory goes that finding depth where fish are holding will increase your chances of getting hits. Depending on food sources immediately available, fish can be holding down at bottom, or swirling near surface, a dropper allows you to explore these possibilities. Dropper Techniques There are two basic dropper combinations. One is sinker/sinker combo, and other is dry fly/dropper, sometimes called hopper/dropper as hopper patterns work very well for this. In sinker/sinker combo, two sub-surface patterns, are used, usually combined with split shot weights. There are two trains of thought in sinker/sinker combo. One is you attach smaller fly first in sequence and then attach larger fly, such as a stonefly nymph and attach a split shot in between flies. The idea here is that smaller fly, perhaps an emerger pattern, will stay in upper portion of water column while stonefly will sink down, towards bottom, where fish is most apt to strike them. Others (including yours truly) take opposite approach. Attach bigger fly first, take that Stonefly nymph for example, put weight above it, and then attach your emerger pattern. The idea is that Stonefly nymph will sink to bottom, and drift in its proper element. And dangling freely behind and above it will be your emerger or whatever smaller nymph you would like. Personally I have had great success with this rigging, although I must say I don't use previously mentioned one very often.
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