smokeonthewater
Fleet Admiral
- Joined
- Dec 3, 2009
- Messages
- 9,838
Re: Need more sun protection on the boat... had a melanoma. 2003 Bayliner 195BR
Dead WRONG except for the "very misunderstood" part....Read below..... There are plenty of other places to read but this explains it well
http://en.wikipedia.org/wiki/Sunscreen
here is a small excerpt from above:
SPF Sun Protection Factor
The sun protection factor of a sunscreen is a laboratory measure of the effectiveness of sunscreen ? the higher the SPF, the more protection a sunscreen offers against UV-B (the ultraviolet radiation that causes sunburn)[2].
The SPF is the amount of UV radiation required to cause sunburn on skin with the sunscreen on, relative to the amount required without the sunscreen.[9] There is a popular misconception that SPF relates to time of solar exposure. For example, many consumers believe that, if they normally get sunburn in one hour, then an SPF 15 sunscreen allows them to stay in the sun 15 hours (i.e., 15 times longer) without getting sunburn. This is not true because SPF is not directly related to time of solar exposure but to amount of solar exposure. Although solar energy amount is related to solar exposure time, there are other factors that impact the amount of solar energy, like the time of day. This is because, during early morning and late afternoon, the sun's radiation must pass through more of the Earth's atmosphere before it gets to you.............................
Read the link above... MUCH more good info
The SPF code is very misunderstood. It is the same protection regardless of number. The number only implies the time it is good for. SPF-30 means you must re-apply every 30 minutes. Getting a higher SPF does not mean more protection. Get a digital watch with an alarm and apply when you are suppose to.
Dead WRONG except for the "very misunderstood" part....Read below..... There are plenty of other places to read but this explains it well
http://en.wikipedia.org/wiki/Sunscreen
here is a small excerpt from above:
SPF Sun Protection Factor
The sun protection factor of a sunscreen is a laboratory measure of the effectiveness of sunscreen ? the higher the SPF, the more protection a sunscreen offers against UV-B (the ultraviolet radiation that causes sunburn)[2].
The SPF is the amount of UV radiation required to cause sunburn on skin with the sunscreen on, relative to the amount required without the sunscreen.[9] There is a popular misconception that SPF relates to time of solar exposure. For example, many consumers believe that, if they normally get sunburn in one hour, then an SPF 15 sunscreen allows them to stay in the sun 15 hours (i.e., 15 times longer) without getting sunburn. This is not true because SPF is not directly related to time of solar exposure but to amount of solar exposure. Although solar energy amount is related to solar exposure time, there are other factors that impact the amount of solar energy, like the time of day. This is because, during early morning and late afternoon, the sun's radiation must pass through more of the Earth's atmosphere before it gets to you.............................
Read the link above... MUCH more good info