TFO Lefty Kreh Bluewater rods use a hybrid of S-Glass for strength and IM6 graphite for performance. Here's how the idea came about:

The Problem

Modern graphite fly rods have come a long way in their ability to be used for fishing for saltwater species. With super fast actions, saltwater rods can develop blazing line speeds and cast big flies long distances with good accuracy. The problem, however, is not casting to fish and hooking them... it's landing them. Graphite fly rods run into trouble when the fish gets to the boat; graphite as a material simply isn't that efficient at vertically lifting heavy weight, something that's necessary when trying to land a 150lb tarpon.

The Solution

We approached our rod designer with this problem and he came back to us with the revolutionary Bluewater design. Bluewater rods use an S-Glass butt section to provide the strength needed to vertically lift the largest saltwater species. S-Glass is a highly specialized variant of fibreglass with a tensile strength of over 1.5 times that of carbon fiber (graphite). Unfortunately, what you gain in strength from S-Glass you lose in castability. Therefore, the remaining sections of the Bluewater rods use IM6 graphite to create a fast action, smooth casting rod. Essentially, this combination of materials delivers all of the benefits of S-Glass without sacrificing the true feel of a fly rod