If there's one thing that's abundant in Costa Rica, it's water. Here it rains 10 months a year, which gives us rivers to spare. There's also enough beaches on both the Atlantic and Pacific to keep you busy for a lifetime.
But, take care. There's a few points you should look into before you take that beach trip, that'll make you experience a whole lot safer.
UV Exposure[]
Costa Rica is located at a much lower latitude than the US, Europe, or Asia. That means we get a whole lot more UV, much harder than any of them. Anyone travelling to Costa Rica should take care to minimize their UV exposure, and avoid painful sunburns that usually take several days to heal.
Special care should be taken when up in the mountain ranges, where UV rays easily reach the ground unobstructed by clouds. If you're visiting volcanoes, sunscreen or sunblock is a must.
Same goes for rafting, horseback riding or any other activity where your shoulders and face are exposed to the sun for several hours. And of course, the universal no-brainer: don't forget your sunscreen at the beach and rivers.
UV is not periodically measured by the local weather service, or if it is, the information is not readily available. Most of the information on UV levels in Costa Rica you might find on widgets or websites worldwide is probably estimated, take it with a grain of salt and protect your skin at all times.
River and beach pollution[]
Rivers in Costa Rica are abundant, but in the metro and coastal areas they can also be highly polluted. One of the lesser-publicized realities of Costa Rica is that most cities dump their sewage raw into the rivers, with no prior treatment. Municipal garbage collection also suffers in many areas, leading people to simply throw their garbage into the water.
How could something so horrible occur in a tropical paradise like Costa Rica? Long story, having to do with lack of infrastructure, urban planning, and just plain ignorance both on part of citizens, and their governments.
Most locals stay away from the rivers for this reason, and from beaches that are near the place where those rivers meet the ocean.
Clean rivers, suitable for bathing, are usually well known by locals and tour guides. Ask around to see if a river is safe to be in, before you try it.
Pollution at beaches is better controlled. Acueductos y Alcantarillados , the state-owned water company, has a program known as "blue flag". Beaches that meet certain standards for bacteriological content in their oceans and cleanup of garbage and debris receive a "blue flag" designation, which is synonymous with safe to bathe in, at least from a human health point of view (see section on riptides below for more information).
You can see a list of blue flag beaches at http://www.guiascostarica.com/bazul/
Beaches that don't have the blue flag aren't necessarily polluted, but you should check with knowledgeable sources before you go swimming there.
Rip tides on beaches[]
Credit: NOAA / Wikihow
Many beaches are notorious for having strong rip tides. Those rip tides are responsible for most drowings that occur locally in the oceans. People simple get caught by the tide, and don't realize it until they're out way too far.
A rip tide is an ocean current that pulls away from the shore, kind of like a river flowing away from where the waves are breaking. It's speed and strength can be significant, up to the point where they can give any experienced swimmer a run for his money.
A rip tide doesn't pull you under (the current that pulls you under is called an undertow), it simply drags you away from the shore along the surface, until you're out too far to swim back. Suprisingly, most drownings occur beause of rip tides, which are much harder to escape from than undertow.
Beaches where notorious rip tides exist have warning signs posted. But if there isn't a sign, that doesn't mean the beach is safe, since rip tides can develop basically anywhere.
You'll know it when you're caught in a rip tide: you'll feel the water dragging you out, sometimes with great speed as if you were caught in a river.
If you're caught, stay calm. There's a trick to escaping. Start by signalling back to shore that you need help: yell or wave your arms above the water. Don't fight the riptide, no matter what. Even if you feel it's dragging you out fast, don't try to fight it. Even the smallest riptide is strong enough to wear you out completely without losing ground.
Start swimming parallel to the shore: swim with the tide, but push to the side as if you were trying to move down the coastline. Keep swimming to the side, until you can't feel the current dragging you out anymore, you've just escaped the riptide. If the current's too strong and you can't swim to the side, relax. Swim out with it until it breaks, the tide usually gets weaker after a couple hundred meters, then swim to the side.
The final part is swimming back to shore once you've escaped. You have to stay out of the rip tide, or else you'll be right back where you started. Swim back to shore with the waves, aim for where you see them breaking. If you're tired, float to conserve your energy, and signal back to shore.
If you get caught in the rip tide while swimming back, repeat the above process until you're out.
Rip currents are a good reason to never swim alone, and never swim at night. Obviously, you should also never swim after you've been drinking, no matter how good an idea it might seem.
Alligators and Crocodiles[]
Alligator taken out of a pool in Jaco by animal control. One of these can easily get away from you if you don't know how to catch it, and send you to the emergency room for stitches.
Beware of alligators and crocodiles in rivers, especially on the Pacific coast. The Tarcoles river is a breeding ground for crocodiles, and they sometimes drift off to nearby beaches looking for food.
If you see one, leave it alone. No matter how small, don't try to catch or move it. Small alligators can easily overpower you and do a lot of damage.
Look around before jumping into pools, especially in the early morning. In crocodile breeding areas, they'll sometimes wander into the pool at night, and stay there, not being able to get out.
Once again, don't swim in rivers without asking a knowledgeable source first. They'll usually know if there's alligators around.
Poisonous fish and water snakes[]
Lionfish
If you're swimming on the Atlantic coast, and especially if you're diving, beware of lionfish on the coral reefs. These fish are real pretty to look at, but have a short temper and a very painful sting. Lionfish have become a problem in recent years, since they have few natural predators on the reefs, and their populations can spiral out of control. Stay away if you see one.
Other stinging fish inhabit the coastlines, but they rarely show up where humans are. Stingrays are the most common, they're usually found by divers or surfers going out into deep waters. Yes they sting, and yes they're poisonous. So don't mess around with them.
You can find species of snakes that swim the rivers and the Gulf of Nicoya. However, they are very rare and keep to themselves above all things. They're not likely to find you. If you should see one, consider yourself lucky: you've just seen something that many dedicated biologists will never see.
Flash floods[]
Anytime you're in a river, there's a possibility of a flash flood. Check this section of the wiki for more information.