My boat had a nice Metz antenna for AIS on the stern pushpit when we bought it. Had very good AIS reception
with it, typically 20 nm or a bit more for commercial
vessels. We thought it was clear of the wind generator
blades, but we were wrong. In a seaway, the antenna aerial met a blade and the aerial broke at the base. We still picked up vessels up to about 5 nm away. As a stop-gap measure, I attached a 3 ft piece of wire to the Metz base. Of course it doesn't stand up, it curls over and down, but it functioned as well as the original antenna.
I eventually turned the Metz base upside down, and let the 3 foot wire hang straight down. I lives there very well and provides good AIS reception.