You may be in for a very good week of fishing at the Cape, as the spring run is in full swing. I have spent a considerable amount of time in Boston the past few weeks and have managed quite a bit of fishing, mostly good to very good.
So far this year I have caught more schoolies on the fly than usual however, they have been much smaller than prior years with a twenty inch fish being a big one. Most that I have been catching are in the twelve to sixteen inch range but there are some in the low thirty range, too. Right now and probably through next week coves, inlets, flats, marshes, tidal rivers, etc., are where the fish can be found and where i would fish. Although it may change by next week, there are not many stripers showing up along the open ocean beaches and rocky shores. The big ones are mostly off shore under the schools of bait although some twenty pounders do wander into the coves, as foodwise the coves are loaded with a lot of everything right now.
That said, fishing has been unpredictable from a timing standpoint. Typically in the spring coves, inlets, flats, marshes, etc., fish best just prior to and after high tide (time of day irrelevant) and just about daybreak (tide irrelevant) however two of my more successful outings were at dead low tide, midday, and I was catching fish after fish in less than two feet of water with some just about keeper size.
Wind has had a tremendous effect on fishing and for the past several weeks the Cape area has seen many days of wind originating from the east and the old salty New England saying goes, "Winds from the east, fishing is least, winds from the west, fishing is best." It is true and nothing kills fishing more than the dreaded northeast wind. If there is NE wind, definitely fish a cove and do not waste your time on the beaches or rocky shoreline. If you get several warm days with a SW wind, definitely try the beaches and rocky shore, as this is the condition that drives the bigger ones off shore towards shore.
When fishing move around and find the fish. For the most part the fish are not staying in one spot and my experience this spring has been if the fish are there they will hit within two to three casts. You may experience a situation where you catch fish after fish for thirty minutes and then it stops. The fish moved. They move with the current and with changes in wind direction so move and find them again. In coves, inlets, flats, etc., the best place to start is on the side that the wind is blowing into if you can. Pay attention to subtle wind direction changes especially at the turn of the tide. It is not uncommon for the wind to die off at tide turn and when it resumes it may be coming at a slightly different angle and that small directional change, along with the tide change, can substantially move the fish.
Typically in a cove the fish move into the cove with the incoming tide. They may follow one shoreline on the incoming and the opposite shoreline on the outgoing. At high tide they generally are deep in the cove and closet to the shoreline.
Pay attention to how the fish are hitting. Sometimes they are only hitting topwater (white foam poppers, white tail with blue and yellow mixed in), other times just below the surface, and other times on the fly's drop. If you are retrieving strip...pause...strip...pause...strip................pause (longer pause because you scratched your nose or something) and you get a take, its not coincidence, that extra pause is what triggered the strike. The same applies to a faster retrieve. Sometimes its the path of the fly. You may be casting and retrieving north to south parallel along the shoreline and then cast and retrieve one south to north and get a strike. That was not random. The fish will tell you what they want you just need to be aware of what you were doing when the fish struck.
Last two pieces of advice - bring along a spinning rod and some four inch poppers and nine inch white sluggos and spin fish to cover water until you find the stripers and since you are going with several friends, spread way out to cover more water and find the fish. Many of these coves have structural features on the bottom that you wont see or know about and and fly fishing is not an efficient way to cover water. You dont need a big meat rod. A six to seven foot freshwater rod with 10lb test is perfect. Each of you pick a five hundred foot stretch to cover with a spin rod and when one of you finds the sweet spot, call your friends.