If it is just the two of you, one hour is usually plenty of time. Photography starts right before the ceremony, captures the ceremony and then you usually have 30 to 45 minutes after the ceremony with just the photographer focusing on the two of you. If you desire photos from other locations, such as our gorgeous Charlotte Amalie historical district or high on top of the mountain with breathtaking down island views, then you would definitely want to add a 2nd or even 3rd hour. Another reason this answer can be tricky is because a lot of it weights heavily on YOUR opinion of the photography. I have a lot of couples that don't even want a photographer and ask us to just take a few simple photos with their own camera. And I have a few brides who put a lot of emphasis on capturing the day and will choose a very high end photographer for multiple hours, even when its just the two of you (because even when it's just the two of you, your day is no less special than the bride that has 300 guests).
Now if you have guests, that's a slightly different story. I remember one wedding where the photographer was frustrated because he had very little time to capture any photos of just the bride and groom because they were constantly asking for photos with Aunt Betty, cousin John, etc. He spent much of that 30 to 45 minutes organizing group shots. When you have a bridal party and a lot of friends & family joining you, you must really consider what you want the photographer to capture. Do you want a lot of images capturing everyone that is joining you? Do you want to get some great romantic photos of the two of you on the beach? If the answer is yes to both, then I highly suggest a 2nd hour. Let the first hour focus on the ceremony and your loved ones (group shots, bridal party shots, some brides even request a separate photo of each couple, individual or family there so they can include that image with a thank you note, etc). Then let that 2nd hour focus on the two of you.
Most of the time, the photographer meets you at the ceremony location but it's not uncommon for brides to want some traditional getting ready photos as well. In this case, it's definitely important to add an extra hour.
I asked Alain Brin of Blue Glass Photography to weigh in on the issue. This was his response:
I recommend at least two hours of photography for any event that has over 15 guests. I also recommend a 2nd hour of photography for couples that want artsy publication style images. These images require more time to capture because the expensive and super sharp prime lenses required to create the pleasing Bokeh (buttery blurred background & foreground effect) demand maximum concentration for precise focusing. If the focusing is off by a mere millimeter, the images become blurred and unusable. Using off camera strobes is also a must for interesting artsy style images. Unfortunately, these strobes require radio transmitters & receivers to communicate with each other. This technology is amazing but sometimes (usually most of the time) very fussy and require precision & concentration to secure desired results. I have attached a photo that I captured today of “Alex”, a new member of our photography team.
Notice the blurred, buttery background and rim light on her hair, shoulders & right arm from the off camera strobe. This style of photography is simply lovely & pleasing to the eye, but simply requires a little extra time to create.
I hope this helps when deciding how many hours you would like to book! And of course, your wedding planner or photographer will be happy to discuss with you what would be perfect for you based on your number of guests and images you would like to capture.