A twist to things looking bigger underwater

[stick500]

Bet you didn't know about this. Most of us do understand that objects look significantly bigger underwater but it's not a constant. It turns out that distance is also a factor in the illusion.

So a carp that is 15 feet away from you looks like a monster, a record breaker. As you approach to take a shot it suddenly doesn't look so big. Then when you bring it to the surface, poor Mr. Carp ends up being a fairly average 32-incher on the tape, compared to when you first envisioned him being 5 or 6 inches bigger when he was first spotted 15 feet away!

After diving and spearfishing since 1975, I finally figured this out and found it confirmed in a scientific paper done by a Psychology Prof. in England that was done some years ago. The paper is kinda hard to get through, but the author confirmed in layman's terms what I had been suspecting in an e-mail she replied back to me.

Have any of you guys ever noticed this effect?



Author's e-mail reply to my question:

Yes, you've got it right. Apparent size is partly determined by apparent distance, and if objects look further away than they are (as in a fog) they look too large, At very close distances in water, objects appear too near and only slightly enlarged, but at further distances they appear too far away and increasingly enlarged. This is because water, even clear water, is like a fog. Of course the effect varies with the clarity of the water, so one can't say exactly what the relation between apparent size and distance is . It also varies with the diver's experience, as some perceptual learning occurs.

[freedivernd]

I once saw this effect on a small doe I was stalking with bow and arrow. But it was just the opposite.. at first it looked small.. then the closer I got the bigger it looked. Just before I shot, it looked huge. At least it didn't have spots... but, it was the first deer I ever got. After that, rule was, no shooting doe unless there are many more around to compare them too.