Millions of travelers have been exposed to the idea of travel insurance without ever actually committing themselves to purchasing some. After all, insuring your vacation trip is something that many people find ludicrous if not outright too expensive to consider, with others arguing that their normal insurance covers any eventuality that could occur when venturing abroad. In reality, though, good travel insurance can often be a lifesaver under certain conditions, though knowing how to make a good purchasing decision isn't easy.

Here's what to consider before you invest in travel insurance, and how to make a good decision when you eventually do decide to buy.

Begin with some tentative research

Before you even consider actually purchasing some travel insurance, it's important that you do some tentative research into your vacation so that you know if any coverage is warranted in the first place. Vacations can be radically different from one another, after all, so it's imperative to establish that you can't assume whether you do or don't need travel insurance in a vacuum but must rather analyze each trip on the basis of its own merits. Climbing Mount Everest, for instance, is infinitely far more dangerous than a friendly scuba trip to a nearby coastline.

You'll need to know departure times and return dates before you buy most travel insurance, as they usually entail covering your entire trip. There are a number of different kinds of travel insurance worth familiarizing yourself before you foray into the market, too, as different trips call for different kinds of coverage. Cancellation coverage is perhaps the most simple and common of travel insurance, and as the name implies it's going to reimburse you for the costs associated with your trip in the event of an unexpected cancellation. For those booking travel arrangements into areas of the world with lackluster infrastructure, cancellation coverage is highly advisable.

Having your trip get delayed, interrupted, or downright cancelled can be frustrating and ludicrously expensive, so review an explanation of the different insurance policies you can rely on in this situation if you're worried about your dream vacation rapidly going South. Next, for those considering extreme sports, travel insurance centered around dangerous activities is worthy of your time and review.

Adventure sports are fun, yet dangerous

Adrenaline junkies who love to race down mountaintops or go high gliding must understand that their risky activities give insurers serious anxiety. After all, there are few moments in your life when you're more likely to get injured or even face the possibility of death than when you're enjoying the thrill of some extreme sports in an exotic location. This shouldn't scare you away from enjoying the adventure of a lifetime, but rather should serve as a useful example of how important travel insurance is for those who engage in dangerous activities in uncertain corners of the globe.

It was recently pointed out in the LA Times that extra travel coverage for lovers of extreme sports is a great idea largely because traditional insurance plans don't cover many of the eventualities that could play out in the midst of a crazy vacation. Medical and life insurance providers aren't idiots and are seldom willing to offer excellent coverage to those adventure sports enthusiasts who engage in high-risk activities on a regular basis. For this, you'll likely need dedicated travel insurance from an agency experienced with other adrenaline junkies, so they'll know exactly what you need.

Making a good travel insurance decision necessitates that you closely mull the possibility of an accident or injury that could follow you for the rest of your life. Nobody wants to think like this, as imagining yourself falling into harm's way can be terrifying in and of itself, yet the risks you're taking when you partake in extreme sports can't be forgotten if you want to enjoy a long and healthy life. For those who aren't embarking on such an adrenaline-fueled adventure, travel insurance may not be as necessary, but those who are foraying into unfamiliar turf with the intention of doing risky activities should seriously considering investing in some coverage early on before their trip.

Know what isn't covered

Finally, if you don't know what isn't covered then you can't make a good travel insurance decision. When national parks are suddenly shut down thanks to government funding disputes, for instance, your vacation will likely suffer but you're unlikely to succeed in claiming travel insurance. A loss of enjoyment is seldom covered, after all, so don't think that a ruined trip in and of itself warrants a claim on your part.

Travel insurance continues to be one of life's great riddles partly because so many people don't know what it does and doesn't cover. Understanding that it's a unique means by which you can protect a costly vacation is important, but you must also know that it's not a catch-all that will always save your investment when things go wrong. Travel insurance may be more useful for adrenaline junkies who crave the thrill of extreme sporting in dangerous conditions, too, so be aware that some travelers need it far more than others.

When considering travel insurance, mull every option before making a final purchase. Closely study your planned trip before it occurs and consider the possibility of a last-minute cancellation. Finally, understand yourself and your pre-existing coverage thoroughly, and you'll be making excellent travel insurance decisions in no time.