The Outbacker ham radio antenna will work on the transom of a sailboat, attached to the railing and properly grounded. I have used this antenna offshore on a 32′ sailboat and it worked fairly well. You will not get the same results from a vertically polarized antenna mounted lower on the transom as you will from an insulated backstay on an antenna tuner but these inexpensive ham radio antennas make a good backup for your SSB. They can be used on the ham bands without an antenna tuner and will work on a couple of the adjacent marine SSB bands. They are of course ham radio antennas and work best at those frequencies. They can make a good backup marine SSB antenna in case of emergency. They tend to perform best when used properly adjusted without an antenna tuner.
You can store these lighweight SSB antennas down below and in case you lose your promary marine SSB antenna you can hook it up for emergency use. I added another coaxial cable to the Outbacker and used a two way HF, marine grade antenna switch. The Outbacker Perth ham radio antenna measures 7 feet with the stinger and is easily stowable. These are not marine grade antennas and are not designed for day to day use in a saltwater environment but they are tough and will withstand the elements when used as an emergency SSB marine antenna. You should remember that they are not tuned for the HF marine bands and you must use a tuner to get those frequencies withouth high SWR. Using a tuner will diminish the antenna’s performance. This is more of an emergency antenna for if all else fails.
For more on the Outbacker as an emergency marine SSB antenna see: Emergency SSB antenna options