[John]

Christine,
If the white swan is surrounded by black water (no reflections) this is where the incident light method comes in. You point the meter away from the swan towards the camera. You don't need to leave the camera position, stay where you are turn your back on the subject and take a reading. What you are doing is measuring the light falling on the subject. No matter what the subject brightness distribution may be you will get a correct reading requiring no compensation. To be really precise, you may need to compensate just a little (1/2 a stop) for really bright or really dark subjects. Many consider this to be the most accurate method. Make sure that any meter you buy can use incident light.