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There are lots of satellites measuring sea level, all show different levels, and have actually had to be calibrated from tide gauges, so obviously tide gauges for the time being, until they come up with a better system, which they are working on.

That's a tough question. I would say it depends on what you are using them for. They have a greater coverage historically but they don't have as great a spatial coverage as satellites.

If I wanted to analyze average global sea levels recently I would go to the data from a satellite like Envisat. If I wanted to analyze the sea level at Miami, FL for the past 100 years, I'd check the tide gauges in Miami.

As Jim z points out, tide gauges could be inaccurate due to the physical location of the gauge placement moving over time. Satellites have their own problems like decaying orbits. Like I said, it's a tough question.

The visual photo comparison method is interesting. Check out the two photos here: http://stevengoddard.wordpress.com/2013/...

Newfoundland, Canada is rising- yes, the whole place is rising. It's called rebound from the trillions of tons of glacier that pushed the land down during the last ice age. Docks have to be extended further and further out from where the shore was when they were originally built because the water level seems to be dropping there. A tide gauge there would show a drop in ocean levels of feet. A satellite would see that it's the land rising, not the water level sinking.

Since you used the word accurate and not precise, I would go with satellites. As a geologist, I see all sea shores as potentially moving up or down depending on the conditions. By that I mean the land at the sea shore is moving up or down which makes apparent sea level rise difficult to accurately measure unless you know the exact rate of subsidence or uplift.

I would go with satellites if the overall coverage is good as well as the quality of individual measurements. For example can the measure whether an ocean floor has moved up or down.

The beach pics are hilarious, one day when you googled how much TAX money was spend on (re)building that beach you will understand why Steve Goddard's comment about "snake oil" is utter stupidity.

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