Which rods to bring is a relatively straight-forward question, depending on whether you are planning to fish for salmon or trout.
For salmon
A rod of 13 feet or shorter for a 7wt or 8wt line is more than sufficient to fish the usk, the 14, 15 or 16-footers can safely stay at home. As salmon don’t typically arrive until April at the earliest there is no need for heavy sinking lines, a floater with a selection of polyleaders is all that you really need.
Flies are a matter of personal choice, Irish style shrimp flies, small tubes, sunray shadows and more have all been known to work on their day, so why not try an Usk grub? Sizes 8 to 14 should be enough to cover most eventualities.
For trout
From the trout fisher’s perspective the Usk is a fairly large river and it can sometimes be necessary to make a relatively long cast, so rods of 8 ½ to 10 feet are best, rated for 4wt or 5wt line. Unless there is a strong wind in play, a 9ft 4wt is about perfect.
Many visiting trout anglers fish too short a leader, which is really only likely to work once the sun has set and the trout lose some of their daytime wariness. It is generally best to fish a 15ft leader at least – which can take some getting used to if you’re not accustomed to it but once mastered will set you up for success.