Galapagos Currents and Dive Conditions. Things you should know.

First and foremost. Diving is a sport where you need to listen to yourself. Diving in places like the Galapagos is as much mentally and emotionally demanding as it is physically demanding. I consider myself to be in decent shape, an experienced diver with over 5000 dives and I lost 8 pounds during my week long live-aboard in early 2010. This is not an article to scare divers. It is an article that I have written with additional content from Teresa Zubi to ensure you are ready when you go.

Gear:

You know this, but service your gear and ensure you go on 1-2 dives within a couple weeks of your trip to ensure everything is working and you feel good with your diving skills. Also GPS, Safety Sausages, Signal Tubes, Mirrors and Sea Snips are a must have. Also you are probably bringing your camera so you will need a very strong and reliable tethering system

Vertical currents and eddies

Down current (vertical current down):

This is an area with fast downward shifting water which is coming from the surface. There are two indicators for this type of current. Fish are not swimming horizontally but vertically, mostly down but also wildly up and in circles. At the same time your bubbles start to go down instead up until the air is sucked down as soon as it leaves your mouth.

When large fish like mackerels are swept down past you, while clearly trying to swim up again it is time to find a coral head or a overhang to press closely against or hide under. Because if not, as soon as the current reaches more than a knot you won’t be able to fin up against it and inflating your jacket won’t help you either!

Up current (vertical current up):

You don’t know how bad currents can be, until you experience a strong up-currents. As every diver knows, to be swept up too fast is very dangerous (decompression sickness, lung damage) and should be avoided at all costs. It is scary if you ever experience it.

Eddies: Washing machine / roller coaster:

An eddy is the swirling of a fluid and the reverse current created when the fluid flows past an obstacle. The moving fluid creates a space devoid of downstream-flowing fluid on the downstream side of the object. Eddies happen when currents run down in small cuts or dips in rock faces. They usually shoot down and do to the shape of the dip the current is pushed into a cylindrical motion. Similar to a washing machine. You can quickly get disoriented, remember bubbles head to the surface.

Ocean Currents

An ocean current is a continuous, directed movement of ocean water generated by the forces acting upon this mean flow, such as breaking waves, wind, Coriolis force, temperature and salinity differences and tides caused by the gravitational pull of the Moon and the Sun. Depth contours, shoreline configurations and interaction with other currents influence a current’s direction and strength.

Galapagos Marine Ocean Currents

Humboldt Current

Predominate in the third quarter of the year the Humboldt Current runs up the west coast of South America from Antarctica. [This current is what brought penguins and fur seals to the Galapagos].

As the Humboldt Current moves through the islands during the 3rd and 4th quarter from June to November, it cools temperatures. The winds come from the southeast and create an inversion over the area. Low straight formed clouds cover the islands much of the day. A drizzle known as garua occurs in the highlands. The garua visibility is lower than the warmer months. Though there is more frequent precipitation this time of year the light rain made it difficult for settlers to collect water during this season. This time of year is referred to as the dry season.

Water temperatures during the cooler months of August and September range from 60° to 65°F [16° to 19°C] in the western islands to around 78°F [25°C] near Darwin and Wolf at the far north of the archipelago. The average water temperature is 70°F [21°C]. From October to December the water temperature drops to the between 60° to 70°F [16° to 21°C] range.

These later months are a good time for green sea turtle sightings [during their mating season] and shark sightings are still high, but rays are seen less frequently.

Panama Current

In November as the Humboldt Current leaves the Galapagos the warm waters from the Panama Current come to ta ke their place. These warm waters dominate the climate in the islands from January to May.

During these months the water temperatures rise to 70° to 80°F [21° to 27°C]. The air temperatures, which are no longer cooled create an inversion layer. The skies are clear and visibility is increased.

The marine life is excellent with many shark, ray and schooling fish sightings. This time of year the waters tend to have the best visibility and the best time of year for diving and snorkelling.

El Nino Current

Every 2 to 7 years the strong westward-blowing trade winds subside. These winds, which normally pull the warm waters to the west and allow the nutrient rich Humboldt Current to reach the Galapagos, fail to leave the islands. Instead the warm water slowly moves back eastward across the Pacific. The food chain is broken and the breeding cycle of many of the animals including;

Galapagos Penguins and Marine Iguanas , which feed off the upwelling is interrupted. Warmer water temperatures also cause an increase in the mortality rate of the young birds and animals. Plants, on the other hand, seem to thrive during El Nino years. Plants, which may not have flowered in years, will flower again due to the excess water.

Peruvians named this phenomenon El Nino, for the Christ child, because it first appears around Christmas. Major El Nino Currents occurred as recently as 1982 and 1998.

How to assess accurately the rate of current?

It is difficult to judge currents, but there are some indicators, which will tell a good observer more or less the rate of current. Fish react according to how strong the current is. Some seek shelter, others thrive in strong current. Observe small schooling fish like anthias or basslets and watch bigger fish like mackerels or trigger fish.

No current:

The small fish are swimming in every direction, in large schools distributed both vertically and horizontally over the reef.

Light current (to 1 knot):

The small fish are aligned, all facing up-current. If they are still in large, spread out schools, the current is around a half-knot. lf the schools are low and wide, swimming close to the coral, the current is closer to one knot. You are able to fin against this kind of current for a short time.

Medium current (1 to 2 knots):

The small fish are now hovering in a school spread out just barely above the coral and finning madly. A current of this strength begins to show in the behavior of the larger fish as well. They face the current and tend to concentrate behind coral heads or in other lee areas (lee =away from the wind / current). Most fish will now swim against the current, so if you do a drift dive, schools of fish will come towards you. In this kind of current it is already difficult to swim against.

Strong current (2 to 3 knots):

In this kind of strong current, the small fish are not seen, because they are all hiding among the branches of the coral. The big fish are gathered in lee areas, or very close to the bottom. On a drift dive in this kind of current you won’t be able to stop and fin against if you want to look at something close up – so just enjoy the ride!

Very strong current (3 knots):

Now you won’t need the fish as an indicator anymore. You are either swept along on a very fast drift dive or hiding behind a coral head. If you move your head around and face the current full on, your mask is fluttering and threatening to fly off, and your regulator begins to free-flow.

Too Much!!

Anything over 3 -4 knots is to strong and this is very dangerous for a diver! In a matter of minutes you can be kilometers away from the boat and if the seas are big, then it will become increasingly difficult to sea a signal tube. This is when GPS devices are a good idea.

If you don’t hang on, use reef hooks or gecko dive then the currents in the galapagos will = very short dives. 3 knots = 5.4 km per hour, so you travel 2 km in 22 min.) or the current couldn’t have been much more than a knot (2 km per hour is 1.1 knot). An example of this is when we dove Darwins arch, we had to Gecko dive for the first 30 min. This starts with a negative (no air in your BCD) backwards roll off the zodiac a quick decent in the current to about 50′. Then you would do what I call upside down bouldering. As you pull yourself along the reef and over to underwater cliff edges. You would hang out in these spots at around 80′ while looking out to see whale sharks and schooling hammerheads.

Then you would release and quickly shoot along the plateau (sandy bottom and reef between the arch and darwin island.) I would often choose to descend into the sand and dig in for a while as Hammerheads would fly overhead, other would continue to ascend and do there safety stops. I would ascend over the plateau, but could see members who were next to me 5 – 8 minutes earlier would be at the far end of Darwin island. Almost 1km away. It is a lot of work for the surface crew, and requires a lot of concentration from the divers. While surfacing you want to ensure you keep clear of caves or eddies that might be present along Wolf and Darwin

Island.

When I was in the Galapagos diving off of Darwin’s Arch we figured we were in a 4-5 knot current. We had 16 members on our boat and after our first dive, we only had 8 members will to test the rest of the dives at Darwin that day.

This is a picture of the ocean currents that was created in 1943

Geko diving:

Sometimes you have to do, what I call “Geko-diving” (geko = lizard) – climbing the coral wall, pulling yourself up with your hands and finning.

I know, this is very bad for the corals, but believe me, if the alternative is being swept down to 40 plus meter (130′) you do it! Try to only hold on to dead coral heads or other areas without life! But there is more you need to watch out for stinging hydroids and scoprion fish. Be careful where you put your hands.

Remember your training. Fin to the surface or use the rocks and dead corral as boulders to assist in your ascent. Do a safety stop. Even if you have to hug a rock. Do not inflate your BCD. When the current eases you will not be able to control your ascent with an over inflated jacket.

I try to surface over the reef top and not out in the blue so in case the current shifts or gets stronger I am only swept down to the reef. Sometimes though it is better to get away from the reef because the current is weaker there. Stop, think and act, and tackle those tough choices.