I've been using Cortlands "Little Tunny" intermediate line for all my Musky and Pike stuff for years. It's formulated for all water temps, while not a floater is sinks very slow and is great for pulling divers down which is a great trigger for Pike and Musky. The short big head turns big flys over fast, and when the lines wet it shoots like a mofo. good stuff.
Cortland - Precision Little Tunny - Clear Camo "All Water" - Intermediate (125')