papa Loc: Rio Dell, CA

Have you ever heard of lens flare?

Abo

Me too.... The sun was behind and to the left.. the "flare" could have come from specular
highlights off the water in front, or almost anywhere with a lens such as the unit on a P900

For a zoom lens to have the range of focal length (and very low cost) of the P900,
I'm amazed artifacts of that nature and others as well, are not far worse and occurring regularly.

A giant lens hood might help... maybe?

gvarner Loc: Central Oregon Coast

Dirty lens or lens flare from the glare off the water.

travelwp Loc: New Jersey

There's a rumor that big foot farts in blue.

Hamltnblue Loc: Springfield PA

When zooming in it appears that the very center is much more pixelated than the rest of the photo.
There looks to be a small wake to hat point.
Was anything photo-shopped out?

Kaib795 Loc: Maryland, USA

This could be a smudge on the lens. Whenever I get sky spots or a haze spot like this, the first thing I do is clean my lens. I mean taking it off the camera at home, first blow off all debris and using clean Q-tips and distilled water, I wet a Q-tip and gently wipe a small area (1/4 of the lens) and turn over to a fresh Q-tip and do another area. Then using clean Q-tips I dry the lens. Do it on both sides of the lens. Afterwards everything is shooting beautifully. I originally thought the spots were on the sensor but it was all on the lens.

Kaib795 Loc: Maryland, USA

Or just use a lens hood if you have one. This often happens from shooting into the sun. Unless you want a back lit glow, put the sun to your back when you shoot. It's just lens flair.

Silverrails

Could it possibly be the beginning or the ending of an Alien "Beaming" themselves to or from a invisible Space ship, Checking out the Weather here on Planet Earth???

bdk Loc: Sanibel Fl.

Ive shot a lot in the mangroves it is very damp back there and I always thought it was humidity creating that spot as Ive seen it a few times. Sometimes you dont see it, but its there.
Could also have been a bit of dampness on the lens.

The sky in that pic is a mess, blown out , ruins the whole photo

saminpa2001

Could it be heat distortion. Water and air temp being different? You may not see it with your eyes but a photo can pick it up.

Electric Gnome Loc: Norwich UK

Could light from the sun behind you have crept into a small gap between your eye and the viewfinder? or is light leak not an issue with mirrorless cameras?

sneddog Loc: Portland, Maine

Hello,
From the information you provided I think the issue with exposure in this photo is that you used spot metering. It looks to me like you spot metered the mangroves or the water as the exposure there is acceptable. Then because the mangroves and water are much darker than the sky that same exposure blew out every part of the scene that has direct sunlight on it.
A graduated split ND filter will fix the problem and give you good exposure across your entire scene.
The weird greenish white line and blob is odd. It's not dust on your sensor. It's not dead pixels. My first thought is that there is something physically on either your lens or filter, if using one. But that is less likely as you stated you've seen this in other photos. Like another member said it could be odd reflections inside you lens. The P900 is a super zoom which means the lens is going to have a lot of compromises in it's construction which could maybe lead to odd reflections in just the right lighting conditions.
I'd clean the lens and filters used to eliminate that being the issue. But if it keeps on happening you'll probably need to send it to Nikon for a definitive answer.

Seabastes

It is lens flare, plain and simple. I have had this occur when using zoom lens where I shot the same scene at different zoom settings and it only occurred at a particular zoom setting. It can also occur with prime lenses at times.

usnret Loc: Woodhull Il

WOW! Did you have your tri-pod on your boat? Heh heh, just kidding. Looks like a pict. taken midstream on a johnboat. 1/40 shutter speed seems a bit slow. ISO a bit high etc. Iv'e learned over time to get in the habit of mixing things up a bit. Different shutter speeds, aperture settings, etc. On an average, (for me anyways), only about 1 in ten are keepers. That's only because I have no idea what I'm doing 90% of the time.

DanielB Loc: San Diego, Ca

The top of the photo is blown out on the highlights and even though the Sun was behind you it could be lens flare from the reflection on your UV filter or even on your sensor (even a slight smudge can cause this). Sure way to prevent this is a Circular Polarized filter.

Just a guess of course - good luck.