The Underwater Seasons During the course of the Musky season, everybody of water undergoes changes in its water temperature as well as changes in the oxygen that is dissolved in the water. As the underwater seasons change, the Musky react to those changes driven by their need to eat and their need to breath. The successful Musky angler must tune into these changes. He/she must be prepared to be flexible with regard to lure selection as well as conducting a better evaluation of water and weather conditions. Late season fishing can be marked by drastic weather changes and dramatic changes in the condition of the water. As the water begins to warm after the long winter months and as emergent vegetation adds oxygen to the water, Musky become more active and settle into their seasonal patterns. For the greater part of the Musky season, most bodies of water are locked into the characteristic thermal distribution commonly referred to as the "summer thermal water pattern". The graphic shown here at the left demonstrates this summer thermal pattern. Water at the surface tends to change gradually in water temperature and tends to have higher levels of oxygen than the water layers beneath it. The thermocline is sort of like a buffer area between the warmer surface water and the cooler deeper water. The cooler deeper water tends to have the lowest level of oxygen during this period of time. Musky tend to populate the upper water levels when they are active and the lower water levels when they are inactive. The hotter the top layer of water, the more likely Musky are to seek a comfortable temperature at greater depths. At these greater depths, they are less likely to be aggressively active.