I made an antenna for my boat but couldn't receive much because my boat is too far from the larger cities.
Here is how I did it.
I bought 25 ft of 'flat twin lead antenna line
' from Radio
Shack. It's the same wire we used from our rooftop antenna to the tv set in the years before cable tv. You'll recognize it when you see it.
I stretched a length of wire across from shroud to shroud. Bared the wire at each end and twisted the wire at each side together so that any current would run in a loop.
Then, I went to the mast and cut the lower wire open and bared it on each side. Leave the upper wire alone.
Take another length of 'twin lead' and bare the ends of it. This wire will run from the mast to your TV (analog style). Twist one end of the vertical wire at the mast to one of the bared wires and do the same to the other wire.
When finished, you'll have a 'T' shaped wire running from shroud to shroud and down the mast to the TV. If you were to apply a current to one of the wires at the TV input, it would run up one side of the vertical wire, across to one end of the horizontal wire, pass through the twisted bare wires, across to the other shroud, through the twist there, back to the vertical wire and down the wire to the TV. You won't be applying a current to the wire but this description helps to explain how the wire shoud look.
I brought in one fuzzy station but one of these day, I'll be anchored near enough a tower to pull down a good signal. It only cost me about 5 bucks.