Blue Water Sailing
It mentions how sailing heeled over may limit your signal reception.
"The distance of sighting a RACON signal will be limited to the height of your radar antenna and power of your radar unit. Sailing heeled over will limit signal reception."
This can be avoided if you are using a Questus Marine Self-Leveling Radar Mount - you will pick up the targets as the radome will stay level with the horizon.
Radar Manufacturers (click on the name below to go to their Website)