Part of the fun of diving is being able to go where others do not usually get to go and see incredible underwater marine life that others may not get to see up close. That being said, make sure that you know what to expect going in so you can prepare for what you will encounter and keep yourself safe. When choosing a diving location, consider the following factors:

• Weather- the temperature of the air and water, weather conditions in the diving area, and common seasonal weather patterns such as frequent afternoon storms can all affect your diving experience
• Water- different water conditions may require different equipment such as a thicker wet suit, more weight, or a different regulator. Always know what you will be getting yourself in to at any dive location and do not do anything beyond your comfort level. 
• Currents- These obstacles can cause a laundry list of dive emergencies including out-of-air, injury, getting lost, becoming fatigued, and decompression sickness.
• Visibility- No one wants to suddenly find themselves in zero visibility conditions. Be prepared for the visibility that is common for the dive location and plan accordingly. If you wanted to see something at 50 feet but the visibility is 8 inches at 50 feet you may want to skip seeing that object unless you are comfortable with low visibility conditions.
• Marine Life- Besides the fun of knowing what you will be seeing when you dive, it is important to know what hazardous creatures you may encounter to avoid injury while diving. No one wants to accidentally brush by a stinging coral or come face to face with a poisonous creature and ruin their trip. Avoid all contact with marine life and pack the necessary items in a first aid kit and wear the appropriate dive gear to minimize risk of injury to you and the marine life.
• On-site Resources- What can you rent? What first aid supplies are available on site? Do you get cell phone reception in case you need to call for emergency services? What other means of communication are available? These are all important questions to have answered before you dive.
• Rules- Each dive site has its own set of rules and regulations that dictate everything from what you wear when diving and what equipment you will need to have to how you access the dive site and what hours you can access the site. Know before you go so there are no surprises that ruin your dive plans.

Having an actual predive packing checklist can help you not forget items that are necessary for your dive to be enjoyable. It can also help you remember to pack extras that may be needed for this dive trip that were not needed for other trips. Below is a pre-made packing list that can be used as a starting point for creating your own. Having the items written down can also help you keep track of your items once you are at a dive site and as you pack to return home.

The human body wasn't designed for an aquatic environment, so its important to understand how pressure affects your bodily functions so you can make informed decisions about your dive plan. Proper planning can help you improve your safety, and reduce your chance of having a serious dive related accident. Some important things to consider are your:

Age and Medical history
Swimming skills and Level of comfort in the water
Level of training
The dive location
Endurance
Ability to Cope with stress
Level of Physical Fitness