Instrument to measure live fish underwater without getting close
or sunken ships, coral heads or anything else
Sea Turtle Scuba Green Lasers are the laser of choice for marine research groups all over the world because they are bright enough to give you dependable visible spots to see.
Some links to information about whale shark research:
University of Southern Mississippi Gulf Coast Research Laboratory
The ECOCEAN Whale Shark Photo-identification Library
Utila Whale Shark Research Project
Maldives Whale Shark Research Programme
Whale shark conservation research in Thailand
Re
Submersible Laser Live Fish Measure
Use with or without a camera
Depending on your requirements for measurements, you don't necessarily need to take a camera and a picture. You can simply place your two dots on a subject and easily estimate the total size. That's much more accurate than trying to compensate for the errors in judgment caused by the refraction of light passing from the water to the air through the lens of your mask.
Taking a picture of your subject gives you a permanent record of the measurement and a more accurate way to compute the size.
The model you see above has the lasers set with a distance of 50cm between them.
If the two dots on the shark are 50 cm apart, the shark would be about 350 cm long. 
If you take a picture of your subject while using this device, you will see two green dots on your subject. You will know the measurement between these dots and can then easily figure the size of your subject by counting how many times the distance between those dots will fit on the body of your subject.
That's a little under 14 ft.
Each one is custom made to fit your needs.
The basic unit comes with two Sea Turtle Green Lasers and the hardware to mount them on the Measure. The basic unit comes without a camera mounting platform. A camera mounting plate is also available for little extra charge.
Since each one is custom made, you might want to contact us if you have a special need for quick service or some special configuration. Contact us for information at info@seaturtlescuba.us
The laser cradles are adjustable to enable you to zero in the distance between the dots before submerging.
You don't need the camera mounted on the lasers if you have someone to point the lasers and someone to take the picture.
You have a choice of size. Pick a size that would be convenient for your project. Too large a size is difficult to maneuver in the water.
We offer sizes 25 cm or 50 cm or 1 foot or 2 feet.
We can also construct it so you can alter the size from 25 cm to 50 cm or 1 ft to 2 ft. by adding a spacer. There is an additional charge for that.