I'm sure I'll hear from 'the king' on this one for being a pu$$y but here goes.

If you're alone on your boat and peeing over the side, getting spooled by a runaway salmon should be the least of your worries. The #1 cause of recreational boating drownings is MOB while peeing.

For goodness sake, if you're alone in the boat pee in a bucket.

Anyhow, that way you can carry the bucket with you to deal with the fish