At home, I currently use 2 homemade antennas for DTV reception: a
bowtie array in the attic, pointed at Buffalo, and a
simple dipole (element length of approx 4" each) stuck on the wall, for local stations, both fed with normal 75 ohm coax, with a simple 2-way antenna switch to select.
This set-up works great. Even the silly little dipole can pick up stations up to 50 miles away, if they're on the antenna's sensitive axis.
Either of these could serve as halyard-raised antennae for in-port DTV I believe ...except that the big one is fugly. It would be less fugly if the back reflector was a mesh or screen panel.
Do try a DIY antenna before plunking down $100+ for an amplified white thingy.