Controlling your buoyancy is key to successful underwater modelling. Ideally, you want to be able to sink when you want to sink and float when you want to float. Everyone has a different level of natural buoyancy, so you will need to learn what works for you! I’ve collected together my top tips from my time as a professional mermaid and underwater model, to help you work on controlling and using your natural buoyancy for underwater photography.
Understanding Your Natural Buoyancy
On average, the human body has a density of 0.98 compared to water (according to Wikipedia!). That means that most people’s bodies are inclined to float, rather than sink.
Your body composition plays a large part in determining whether you’re more sink-y or float-y; muscle and bone are more dense than water and sink, whereas fat will float. Women naturally have a higher body fat percentage than men and so are more likely to be inclined to float – great in a shipwreck situation, but potentially more of a challenge when modelling underwater.
When it comes to learning how to control your buoyancy for underwater photography, you could work on changing your body composition, but that tends to be quite a long-term fix! In the short term, buoyancy control is mainly about controlling the amount of air inside your lungs, which effectively act as a floatation aid when full of air.
It’s also worth remembering that the salinity of the water will make a difference: if you’re swimming in salt water, you’ll always be more floaty than you are in a pool.
If You’re Floating Too Much
If you find that you’re constantly floating to the surface when modelling underwater, the first thing to think about is your breathing. Our natural instinct is to take as deep a breath as possible before submerging, in order to be able to last as long as possible underwater; however, having lungs full of air is likely to make it difficult for you to pose in place for long.
As you’re about to dive, take a deep breath and then puff out a little air before going underwater; you’ll need to experiment with this to find the exact amounts of air you need to breathe out in order to be able to float neutrally in the water or sink to the bottom and stay there.
If you’re a very competent swimmer and this is something you’re struggling with, you can also think about incorporating diving weights into your costume. Scuba divers use these to compensate for the buoyancy of their equipment. You can purchase small amounts of lead shot ballast online in pouches which can be hidden or incorporated in weight belts or costumes. However, being weighted down always has the potential to be dangerous – your weights should be quick release, and you should be careful not to weight yourself down too much. It’s always good practice to have an agreed hand-sign so that your photographer and/or assistants know if you’re in difficulty and can come to assist.
If You’re Sinking Too Much
If on the other hand, you find that you’re sinking too much and you’re not able to simply float in place underwater, firstly make sure you’re taking a good deep breath before submerging. You may find that it’s your natural instinct to breathe out as you’re diving down in the water, thus making it easier to dive down quickly, but if you tend to have negative buoyancy (i.e. you sink!), you need to hold on to that breath of air while diving.
If that still doesn’t make a difference and you find you tend to sink straight to the bottom, this is probably a natural effect of your body composition. You’ll need to try to get good photographs on your way to the bottom, while swimming, or after pushing off from the bottom of the tank or pool for an underwater jump.
Playing With Buoyancy For Underwater Modelling
Finally, it’s worth thinking about how you can capture great shots underwater while working within the limitations of you/your models’ natural buoyancy.
If you constantly float and can’t stay in one place for long, you’ll need to go for shots with more movement; try diving down to the bottom of the pool or tank and then allowing yourself to naturally float up through the water (remember: if your lungs are full of air it will mean that your torso floats up first, so you will pretty much always maintain a vertical body position if you do this).
Having a model with negative buoyancy who sinks straight to the bottom can be great for setting up more complicated poses or scenarios, or working with props.
Having two models with different natural buoyancy affords a lot of possibilities for underwater photography; having one model with negative buoyancy who is able to remain at the bottom of the pool means they can act as an ‘anchor’, who can hold the more floaty model in place. This makes it much easier to catch the perfect shot of more than one model, while keeping the underwater ‘feel’ in the photograph.
More tips for underwater modelling
This blog post is part of a series of articles on underwater modelling and photography, based on my experience as a professional mermaid and underwater model. You can read more top tips for underwater models here, or learn how to open your eyes underwater here.