sweaty and sandy

Totally new Zen port.

Try to take some photos on the beach with strong waves.

I found some "sweat" and sand on the corner of my Zen dome port.

(I am sure inside the port is clean.)

Is there any easy way to keep dome port clean all the way underwater?

Spit, smear, and rinse?

Any specialized detergent works?

I'd be really surprised if either mark was from the outside of the dome...

Tim

It looks like your sensor is quite dirty.