There are many stocks out there with similar symbols. Here are three in the same industry:

Oceaneering International, Inc. (OII:NYSE)

Input/Output, Inc. (IO:NYSE)

Oil States International, Inc. (OIS:NYSE)

OII is an oil and gas services company offering engineered services and products for deepwater applications. It operates manned diving vessels for deepwater interventions, offshore production systems, and other industrial equipment.

IO provides seismic data, design planning and surveying equipment to oil and gas companies. It operates both on land and in marine environments

OIS supplies offshore vessel and rig equipment, pipeline products, marine winches, and various services such as inspection and repair of equipment, and the design and fabrication of sub-sea products.

Let's see how these three stack up against each other.

OII and OIS both have a large dip starting from late spring, but IO has continued its path toward higher ground. All three of these stocks are necessary for the oil industry to progress, but you could say IO is a leading indicator of more business for the other two.

With seismic surveying capabilities in high demand, one might assume that oil and gas producers are doing a lot of “pre-drilling” activity.

Other oil services, like pipelines and rigs will follow.

Here's the breakdown for each:

Oceaneering International, Inc. (OII:NYSE)

52-week change: 54.50%

52-week high: $47.23

52-week low: $24.48

Profit Margin: 9.32%

Operating Margin: 14.93%

Quarterly Revenue Growth (yoy): 28.20%

Quarterly Earnings Growth (yoy): 117.60%

Input/Output, Inc. (IO:NYSE)

52-week change: 78.98%

52-week high: $13.87

52-week low: $6.75

Profit Margin: 6.79%

Operating Margin: 8.69%

Quarterly Revenue Growth (yoy): 38.30%

Quarterly Earnings Growth (yoy): 8.60%

Oil States International, Inc. (OIS:NYSE)

52-week change: -3.04%

52-week high: $43.87

52-week low: $25.00

Profit Margin: 10.05%

Operating Margin: 15.04%

Quarterly Revenue Growth (yoy): 21.60%

Quarterly Earnings Growth (yoy): 65.10%

This data shows a bit of a more complex story than the comparative chart above. IO appears to be performing better, based on the chart, but a glance at profit margins and revenue and earnings growth shows you that there's more beneath the surface.

One thing investors should keep their eyes on is third-quarter earnings. IO announced it's maintaining its 25-36 cent outlook in the face of Thompson Financial analysts' forecasts of 14 cents per share. If it misses its outlook, expect the stock to fall on the news.

To be fair, other analysts are expecting 32 cents per share, and for the company to meet its 2007 outlook of between 45-60 cents per share.

Longer-term investors should expect a blip when the next earnings are released in the new year.

Again, IO could be a leading indicator of how other oil services companies will perform. As we edge into 2007, you might expect to see better movement from both OII and OIS.