Before every dive, you should evaluate the water conditions and decide if they are suitable for the dive you have planned and your skill and experience level. This is a critical aspect of safe and enjoyable diving.
As long as you choose a dive site and conditions that are within your training and comfort level, you will have a great time. Anytime you plan to dive at a new site, it is important to get an orientation of the site's above- and below-surface features from someone who knows the site. The nearest dive store may be the best source of information, but don't discount the help of a local dive group or club. This information about the dive site can make the difference between a great dive and a rotten one.
Environmental considerations to consider include temperature, visibility, tides or currents, bottom composition, marine life, any sensitive or dangerous areas, and impact on surrounding land and landowners.