For 5m you can make something like this, floating video transmitter for less than $100
https://www.google.ca/search?q=mini+video+transmitter&tbm=isch&tbs=rimg:CSuCXHanHo0YIjiKlqoyDRmaAsNIzOlNssuC7XvA59FqQ1eNoMCFOs7LoU8wzwc8eFRZyxVhJzWFGzXLJnVJa45QBSoSCYqWqjINGZoCEYQuGyMoN49GKhIJw0jM6U2yy4IRnBMFDlchW40qEgnte8Dn0WpDVxEs9aF7_1UBmuCoSCY2gwIU6zsuhEcL-fXp2DA-hKhIJTzDPBzx4VFkRrdZRsarnw0MqEgnLFWEnNYUbNRH62jJfopQ2gCoSCcsmdUlrjlAFEfLpUE4spmnN&tbo=u&sa=X&ved=2ahUKEwjJpPW74uHaAhXh3YMKHaPVAa8Q9C96BAgBEBs&biw=1440&bih=787&dpr=1#imgrc=oLlMKhyzrl5ffM: