Wind, storms and exposed conditions are just part and parcel of living here on the coast. Hedges can enclose, provide shelter, privacy and food for birds. Although there are lots of choices for hedges coastal conditions limit the species you can use successfully. Salt winds are a killer for so many inland native plants.
Once you have decided what you wish to accomplish, taking into account the soil conditions you can then look at the species of plants to use. There is nothing more annoying than having some but not all of your hedge surviving. You need plants to be spaced correctly, too close is an unnecessary cost and too far apart they are a row of trees not a hedge. Some hedges can be left to do their own thing but most will require some sort of maintenance. Stay away from fast growing plants as they will cause you trouble and who wants to be trimming a hedge once a week. Slow is good.
Coprosma repens, Taupata would have to be one of the hardiest coastal hedging plants and is happiest growing in exposed coastal conditions. It has shiny foliage with showy orange fruit attractive to birds. Corokia species and cultivars also make excellent hedges covering a range of size options. They are happy growing in sandy ground around our local beaches. The Corokia can be kept to a perfect form and produces yellow flowers followed by bright red berries.
Many of the Pittosporum species are useful but Pittosporum crassifolium or Karo creates a large salt hardy hedge. Once you have provided shelter it is amazing what you can grow here.