?? camera settings for our green water

[freedivernd]

Tomorrow I'm giving the canon and housing a try in the river and although because I'm "just snorkeling" I'll be able to make adjustments easily I'm wondering what's the best to do with the flash... and the mode setting.. I'd like to leave it on auto to start with.. but am wondering if I should disable the flash or use the diffuser, also I'm wondering about the "underwater" mode.. that's supposed to limit the flash and take out the blue.. and that sounds like something for bonaire not for the ottertail.  Just wondering what the best setting to start with might be.  I don't know what we'll have for vis or sunlight tomorrow either.  I'm planning on using mostly the video mode anyway.. and using that at the lowest setting.. but there I have the option to use the "underwater" mode also.
I explained all this and more in an earlier post that disappeared..... shucks.
Fred