UV Forecasts

  With summer around the corner many mariners are preparing their vessels for the upcoming season. Much of their toils will be directed at the safety and proper running of the craft. Flares in date, life-jackets checked, radios etc.
  One small thing that maybe overlooked is the prevention of sunburn. Many mariners and their passengers will get burnt this year leading to a painful few days with possibly longer term effects.  Sunburn is a reaction to exposure to ultraviolet (UV) radiation. The top layers of your skin release chemicals that cause your blood vessels to expand and leak fluids, causing inflammation, pain and redness. Without protection, UV radiation will immediately start to penetrate deep into the layers of your skin, damaging the skin’s cells. Skin turns red within two to six hours of being burnt. It will continue to develop for the next 24 to 72 hours.
  In southern states changeable weather often leads to cases of sunburn.
  For example, on a summer’s day with a northerly wind and temperatures above 35°C most southern mariners would be using sunscreen and reapplying it often. With a change going through overnight and a southerly wind blowing the next day, a temperature of 18 °C and some cloud and the need to apply sunscreen seems to be less. However, this is wrong, as when in the sun on either of the two days the UV exposure is exactly the same.
  As part of being a responsible skipper you should;
  • Check the UV forecasts and alerts when getting your weather for the day,
  • Have a supply of 30 plus (in date) sunscreen available,
  • Suggest that crew/passengers use sunscreen,
  • Have plenty of cool water for drinking,
  • When inviting passengers or arranging a crew remind them of sun dangers and to bring appropriate clothing, hats and sunglasses (preferably on lanyards).

Understanding your sunscreen

How do they work?

  Sunscreens with Titanium Dioxide or Zinc Oxide work largely by reflecting ultraviolet light, effectively ‘blocking out’ sunlight.

Do sunscreens have a use-by date?

  Sunscreens break down with age; the use-by date is good if the bottle was stored at less than 25°C. This is important for mariners, as the sunscreen may have been “cooking” inside your closed up vessel where temperature could regularly be higher than the external temperature and above 25 degrees, reducing the shelf life of the product.

What does SPF mean?

  SPF or Sun Protection Factor gives an indicator of the level of protection given.
  The higher the number the better the protection. In Australia SPF ranges from + 2 to +30. Some overseas products have SPF higher than +30, however, the Cancer Council maintain that sunscreen can only be reliably tested to +30.
  Broad Spectrum means the sunscreen will filter both UVA and UVB rays.
  Light from the sun is divided into categories by its wavelength; ultraviolet, visible and infra red. Ultraviolet light is further divided (by wavelength in UVA, UVB, UVC).
  UVC does not usually reach the earth’s surface due to the ozone layer. UVB does not penetrate deep into the skin, it varies by season and is at a maximum over summer. UVB is linked to melanoma, cancer and sunburn.
  UVA penetrates deeper into the skin than UVB and is linked to ‘leathering’, spotting and wrinkling of the skin.  Water-resistant sunscreens are best for water sports, and when you are active or likely to perspire while outdoors.
  The Bureau of Meteorology’s UV forecasts can be found on the internet at http://www.bom.gov.au/products/UV UV alerts are also part of the major city forecasts.
  Further information on sun protection can be found at the Cancer council website http://www.cancer.org.au/Home. htm and follow the links to your State.

*Malcolm Riley is the Public and Marine Officer for the Bureau of Meteorology in Hobart. He has worked in all States with the exception of QLD and is a Master V. He gives education courses on Marine Meteorology.