Posts Tagged ‘In the Water’

How to Ascend from a Dive

Friday, March 18th, 2016

A recent accident in Koh Phi Phi’s Maya Bay, Thailand, wherein two surfacing Russian scuba divers were struck by a speedboat propeller, resulted in one of them losing a leg and the other receiving deep lacerations. When accidents like this occur, it’s worth revisiting the safest possible ascension procedures. The exact details of the accident are still unclear, so this article is in no way intended to assign blame or claim to know how it could have been prevented. Rather the incident serves as a reminder that, as scuba divers, we must always be vigilant as we ascend in mid-water to minimize the risk of run-ins with passing watercraft. Here are a few of our tips on how to ascend from a dive.

Carry a Dive-Flag Buoy

If you’re on a guided dive in an area with boat traffic, the divemaster should have a dive-flag buoy, which will accompany your party on the surface during the entire dive to let watercraft know exactly where you are underwater. When it’s time to surface, do so as near as you can to the buoy. If it’s just you and a buddy on a dive, one of you should deploy the dive-flag buoy for the same reasons. 

Start Early

Once it’s time to ascend, remember that a proper ascent takes some time, so make sure to begin by taking into account your remaining air, your no-decompression limit and personal factors, such as cold and fatigue. Ascend while you’re still fresh and on top of things. 

Go Slow

Most organizations recommend a maximum ascent speed of 30 feet (9 m) per minute. Orient yourself as you begin your ascent, getting an idea of where you are in terms of your planned surfacing point. Start looking up to get an idea of the conditions above. Is the sea calm or choppy? Do you see a lot of boat traffic, or do you have the water to yourself? As you ascend, also keep an eye on your depth gauge and timer to make sure you’re rising slowly enough. 

Stop

Even if it isn’t a requirement for non-decompression dives, pretty much all dive organizations and dive computers recommend a safety stop for any dive deeper than 33 feet (10 m), typically at 15 feet (5 m) for three minutes. Use the time during your safety stop to scan the surface for any boats (including your own dive boat), kayaks, or other vessels you may need to navigate around. Listen for propellers as well, as you’ll hear a boat much sooner than you’ll be able to see it. You won’t be able to determine where it’s coming from though, so watch the surface for it.

Surface

When you’ve finished your safety stop, become neutrally buoyant before beginning your ascent, and maintain neutral buoyancy throughout. Fin very gently if you must to ascend. Keep the ascent rate as slow as possible, but don’t spend the entire time looking at your dive computer. Instead, look around, scanning the surface. Rotate as you ascend to give yourself a 360-degree field of vision. Most organizations recommend that you ascend with one hand above your head, holding your low-pressure inflator at the highest possible point to allow you to quickly release air from your BCD if your ascent becomes too fast. This is also partly to ensure that if you do have an unfortunate encounter with a boat propeller, at least it will be your hand and arm that takes the hit instead of your head. If there’s boat traffic overhead, you may want to delay your final ascent until it’s clear, air-permitting, or swim to another location. 

Come up Close

Ascend as close to your dive boat or dive buoy as you can, as mentioned above, since other boats will typically keep their distance. If you have neither, and there is boat traffic in the area, send up a DSMB before surfacing to give boats and other vessels fair warning that people are coming up.

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Project Ariadna Will Offer GPS for Divers

Saturday, March 5th, 2016

Although we’ve all grown accustomed to the (usually) accurate directions provided by our GPS-based smartphones, underwater, we must rely on compass navigation. The researchers behind Project Ariadna have spent more than six years trying to change that, creating the first personal, underwater, GPS-based navigation technology. The last remaining milestone: Miniaturizing it into a wrist-worn device.

Divers cannot use terrestrial GPS satellite technology, as the high-frequency signal can only penetrate approximately 2 millimeters into the water. Over the years, there have been a number of attempts based on ultrasonic signals, but limitations caused by signal reflections and many other environmental drawbacks have made these products impractical.

The idea behind Project Ariadna is to use an inertial navigation data fusion principle to calculate a diver’s position when submerged. At the surface, the GPS signal is used as a point of reference. Immediately upon submerging, Ariadna switches to its inertial data fusion technology. Using 11 independent sensors and an extremely sophisticated algorithm, it processes data in real time and calculates the movement vectors.

As a result, a diver can monitor graphically, in real time, his exact position and executed route on the map. Ariadna technology provides a diver with precise, turn-by-turn navigation along the planned route. After diving, the resulting 3D-dive log can be reviewed with such tools as Google Earth for post-dive analysis and sharing with other divers.

Underwater “Google Maps”

Project Ariadna gives divers access to all the familiar features of common GPS navigation systems, such as Points of Interest (POI). The list of POIs in Ariadna’s system enables divers to plan intriguing routes, even in new dive sites. It also possible to add a new POI during a dive to mark new discoveries, as well as to attach them later on underwater photos and videos.

It’s possible to review and accurately allocate pictures taken along a dive route by using Google Earth software features during post-dive analysis. One of Project Ariadna’s big goals is to eventually create an underwater map of the world with underwater POIs already marked and ready for easy route planning.

With its ability to record, save and share routes with precise POI markings, it’s hoped that Ariadna will be a useful tool for scientists, underwater biologists and explorers. The precise-position information provided by Ariadna as GPS coordinates will make all location-data related tasks, such as cave surveying and mapping of underwater archaeological sites, more effective and straightforward. Data collected with Ariadna can also be exported to external software for further processing.

Improving Diver Safety

Losing your way in bad visibility can increase stress levels and lead to panic. Anxiety can also result in increased gas consumption and an urge to ascend too quickly, or to surface in a dangerous spot. Using Project Ariadna may help divers reduce stress by providing constantly updated location awareness, as well as other safety-related features, such as Remaining Bottom Time and Distance (RBTD), an extension of the currently used RBT technology. To further improve dive safety, Ariadna offers the “Navigate Home” function, which graphically indicates the shortest route to the dive entry point, and is activated with a single press of a button. Although the technology is already operational, the commercial launch of Project Ariadna is expected in 2017.

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Say Goodbye to Fogging Dive Masks

Friday, February 12th, 2016

By guest blogger

What diver hasn’t envied the mythical mermaid (or merman), who’ve no need for oxygen tank and certainly no need to spit into a mask to see clearly? But, since divers don’t live under the sea — as much as we’d like to — we are pretty much stuck with the apparatus needed to enjoy the wonders of the deep. Now, as someone who loves the ocean, I’m sure you’ll agree that good gear makes for a good dive, with the same holding true for lousy gear laying the groundwork for a dive full of mishaps and misfortunes.

Most of us dive as a hobby, for the love of the sport…weekend warriors if you will. And since our free time is precious, we must make the most of what we’ve got, which means good pre-planning and good gear. Can you imagine arriving somewhere and realizing you forgot to fill the tanks? Highly unlikely.

Or, how likely are you to just show up at a dive shop with no reservation and expect to have it all come together and go? Also very unlikely. My point is that if you time, energy and resources into having a great dive experience, why would you risk having a fogged up mask?

Dive-mask fogging is an ever-evolving issue — there are better masks, better polycarbonates, anti-reflective lenses, and smart lenses, and yet the issue remains. And no matter how many articles are written on the subject, folks still fall back to that age-old remedy, spit.

Now, if you don’t mind winging it and hoping for the best, then spit might do you just fine. But, if your goal is to make the most of the experience, then why not use the best product available to combat fogging on eyewear.

Sven Can See is an innovative solution to combat fogging on eyewear. No matter the use, Sven Can See will solve the fogging issue. What makes this product so unique is that it uses no alcohol to solve the fogging problem. The folks at Sven Can See delved into to the root of the fogging issue and found a solution within nanotechnology, whereby they keep the water molecules that make up fog from crystallizing. No fog.

Sven Can See is also perfectly clear. Oh, and it has a really cool back story. You see, Scott Newman, the creator was looking for a name for his new product.  “When my daughter was really little,” Newman says, “I used to tell her bedtime stories of Sven the Mountain Climber.”

The key to success with Sven Can See is twofold. First, less is more, so use only a very little drop and rub it with your finger onto the entire lens surface. Next, you must apply it to a dry lens. And if you rest between dives, “dry and reapply.”

Sven Can See is the real deal. It’s a very cool product that has no alcohol, no ammonia and no odor. And it really works. And, if you are not 100 percent satisfied, Sven Can See has a money-back guarantee. Check it out today, and don’t let mask fog ruin even one more dive.

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Scuba Diving Checklists: Wreck Diving

Friday, December 18th, 2015

Of course there’s standard gear for every dive: wetsuit or drysuit (or simply a rashguard if you’re in very warm waters), tank, BCD, regulator, fins and mask. Add a bit of personal gear, such as a camera, and on most dives that’s pretty much all you’ll need. But certain types of dives or those with a specific purpose call for specific pieces of equipment that you wouldn’t normally bring.

In this series of articles, we’ll help you put together checklists for various types of dives, this time for wreck diving.

Gloves

Ships are often made of steel, and when submerged — especially in saltwater — they rust. This, combined with damage from their sinking and general wear and tear, means that wrecks often contain sharp, exposed edges that you could easily cut yourself on. And because of the rust, a cut can very easily become infected. So if you’re exploring, especially inside a wreck (with proper training), you may find yourself touching surfaces, particularly if you use the popular pull-and-glide technique. Wrecks can be traps for jellyfish, catching their poisonous tentacles on the structure, so you also risk stings from these. Wearing gloves protects your hands, so wear them even if you’re diving in warm water where you wouldn’t normally need them. Even a pair of thin gardening gloves can be enough to offer that little bit of protection you need.

Exposure protection

You might want to consider wearing a bit more exposure protection that you normally would when wreck diving. If you’re diving in warm weather, a shorty might seem adequate, but if you accidentally brush the side of the wreck, you run the same risk of cuts and burns mentioned above. So a thin, full-body wetsuit can be very helpful.

Dive torch

If you’re venturing inside a wreck, regardless of whether you stick to the light zone, or if your training allows you to venture deeper, you’ll need a dive torch to light up the dark corners. And even if you stick to the exterior, a dive torch will illuminate portholes so you can see what’s inside. If you’re penetrating a wreck, make sure you also bring at least one backup light, and preferably two.

Line reel

If you need to measure the wreck, a line reel is a great tool, but if you’re venturing inside the wreck, a line reel is an absolutely essential piece of gear to help you find your way back to the entry point. In very low visibility, a line reel attached to the shot line (or anchor line) will guide you back to your boat.

Redundant air source

Again, if you’re venturing into that wreck, a redundant air source is a good idea. If you’re sticking to the light zone, a pony bottle or a Spare Air can be enough, but if you’re heading deeper into the structure, a full double set, with two full tanks and separate first stages, is the right choice.

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