Wise words Dave
Racing tides don't mix with fog, so however well I know an area I usually carry an orienteering compass in my wader pocket just in case. This comes in handy for lots of things, including bearings on boats, features and other anglers (sneaky).
I've heard we have also got a few unexploded WW2 shells and stuff out at the low water mark over here (a long way from land). You wouldn't need a solid tipped LRF rod to feel one of those "bite" (pass me that red harp), but if a your 'phone was in a pouch at least it might survive the next high tide.
Seriously, remember to leave some air in the pouch and to clip the lanyard to your jacket.