Martha's Vineyard - fly rods, reels and lines
Although I use the same rod and reel for all of my striper and bluefish fishing, having the appropriate fly lines to address the varying conditions and locations on the Vineyard is critical.
For the record, I absolutely love my Orvis T3, 9-weight, two piece rod. It casts smoothly, has a nice touch and I'm an Orvis addict. Tangentially, I read and hear so many people recommending four+ piece rods. There's too much to go wrong, the guides getting mis-aligned, the ferrules becoming loose, etc. I simply don't get it. My reel of choice is Redington's Brakewater. The downside of the Brakewater is its upkeep, requiring you to constantly lubricate and grease its parts. But, it handles big fish really well, making it worth the extra effort.
Getting back to fly lines, you need three different lines to fish the Vineyard, a floating, an intermediate and a shooting head. I use floating line for the majority of my sand eel fishing. Floating line with a sand eel is always my preferred setup when fish are breaking the surface. An intermediate line comes in handy when fishing sand eels, too, but I typically tie on a deciever when fishing at an intermediate depth. Shooting head is the perfect line in a rip, with a deceiver or half-and-half. Just for the record, all of my biggest fish have been taken on floating or shooting head lines.