I have always fished alone, but I have been invited to fish as a second rod on a local chalk river (River Frome). I am not sure how this would work. The beat is just under a mile long.
Any help would be welcome.
Even if the rules of the beat allow two rods to fish at the same time I would go with the suggestion of taking turns.
You can learn a lot by watching the other rod fishing and the reactions of the fish to the fly. Four eyes can be better than two and in some situations there is the chance for teamwork, one spotting and one casting for example although on the relatively small and very clear Frome just keeping back out of sight might be better!
Divide the beat in half & fish half each until a mutually agreed time, then change over. Both of you get plenty of water to play in and nobody gets in anyone else's way. Have lunch at the change-over & if you both stay for the evening then just fish as you see fit.
Have a dry fly set up and a nymph or Duo set up , let the dry fly man in first to cover tail and the middle part of the pool , then the nymph man can cover the faster head of the pool .
You could have your own individual pool , if your mate catches up with you then let him pass you by .
Sometimes when fishing in a pair you can have 6 casts each and that works well on narrow rivers and smaller rivers .
Another idea is to go fish for fish , another thought is to let one rod work downstream , example spiders down and across or even downstream dry fly fishing , the other rod then uses upstream methods .
Last suggestion is to split the beat up in half , meet in a arranged place to consider the best tactics .
2 more suggestions let one angler fish virgin water in the morning , the other rod fishes second hand water , fishing second hand water and catching fish does improve you as a angler . In the afternoon just reverse it .
This one works better on wider rivers and wider stretches , each angler fishes on opposite banks , you have your owns sides and share the middle part of the river .