I'm looking for a powerful portable power solution to use on my kayak in
fresh water.

I'd like to:

1) mount an Absorbed Glass Mat Marine Deep Cycle 12V battery inside a large
waterproof Pelican case. The Pelican case will be either tied down or
mounted to the kayak.

2) hook up a Marinco SEALINK Receptacle with Alligator Clips to the battery
( http://tinyurl.com/4nme4 )

3) plug a Wagan 3 Way Socket with Battery Analysis into the Marinco 12V
receptacle
( http://tinyurl.com/46j7v ) - is there anything available more
sophisticated than this?

4) plug my electronic devices into the 3 available sockets on the wagan
device with the ability to determine the status of the battery.

Attaching the Marinco Alligator clips to the battery, and hooking up the
devices will all take place before entering the water and never take place
while on the water. The electronic devices I'm using require little or no
interaction. If interaction with an electronic device is required, it will
take place as far away from the battery as possible and only if my hands are
dry and the water is calm.

If conditions get too rough, devices are turned off, pelican case is closed,
sealed, and waterproof.

The pelican case lid will be opened slightly to allow ventilation and opened
and aired out periodically for greater ventilation.

My goal is to have access to portable power on the water with my kayak
without the risk of electrocuting myself or anyone else!

I'd like to be able to relax and use my power supply without being anxious
or uptight with concern over electrocution.

Is this approach safe?

Are there any other precautions I should take into consideration?

what to do, what not to do etc.

Thanks for any info.