In Fishing tournaments (like Bass Master Classic), how do they know the weights of fish before the weigh-in?
They have a leader-board with weights down to the ounce after each fish is caught, before the official weigh-in. Just curious.


they have already weighed the ones the divers underneath the boats have.
Its basically a guess. They have a pretty good idea of the weight of the fish, (from pre fishing) by length + girth.
They can not get it exact but will usually be in the ball park……why they always state his weight/standings are always an estimate.
In a tournament there isn’t time to weigh a fish, it is an educated guess. If need be they will measure the fish with a fishing ruler or will have ruler tape (sticker) some where on the boat. There is a minimum length that can be caught and having a ruler on the boat comes in handy if filling the live well with larger fish gets tough.
If you are wondering how to weigh a fish, you can pick up a fishing scale at any sporing goods store even wal-mart.