Choosing a traina rod
Choose the line class for the fish and the drag you intend to run. The ladder goes 1-4, 2-6, 4-8, 6-12, 8-15, 12-20 and 20-30 lb. Coastal work on bonito and bass lives at the light end; tuna and larger pelagics need the top. The class is what keeps rod, drag and line consistent, so match the whole system rather than the rod alone.
Do not read the lb figure as a casting or lure rating. It describes the line, and some rods separately quote a trolling weight in grams for what is dragged behind the boat. Two numbers, two questions.
Take length as given. Nearly everything here sits between 1.7 m and 2.4 m and 2.1 m is the commonest size. These are short because leverage over a long fight matters and casting does not.
Look for a unibutt if you are fishing the heavy end. The gimballed fitting seats into a belt or a fighting chair and puts the load through your body instead of your arms. On a 20-30 lb class rod it is the difference between a fight you can finish and one you cannot.
Check the closed length if the rod travels. Several models quote one in the notes, which points to a build that packs down. The telescopic marker is unreliable across this range, so the closed length is the more useful number.