 A grilse is a salmon that has gone out as a smalt and has come back the following year as a one sea winter fish. Usually they start coming in the river about the end of June at about four pound in weight and each month they're out at sea. Coming in that year they put on about a pound of weight per month and your two sea winter fish are the ones that come back after their second year at sea and your three sea winter fish are obviously the bigger boys but they all, having spawned, attempt to get back to sea. Your male fish do not make it because they run out of gas looking after the reds after spawning.