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represented by 100-year wind and current speeds combined with a sea state with a

return period of 10-year should be considered.

The shear current is generally considered linear with depth or bilinear. In deep

water, the current disappears near the bottom. Near the sea floor in shallow water

the current profile is logarithmic due to bottom shear.

Besides introducing non-zero mean velocity in the water particle, current alters

the shape and size of the waves. Moreover, the current is stretched under crest (or

compressed under trough). An acceptable approximation for uniform current is to

move the current profile up to the free surface straight up above the mean water

level. For a linear shear current, a stretching formula similar to the Wheeler

stretching for waves may be applied. For irregular waves, an extension for

stretching current may be used based on the regular waves as stated above.

Loop current is a part of the Gulf Stream system and loops through the Gulf of
Mexico continually. It enters the gulf through the Yucatan Channel and exits

through the Straits of Florida oscillating north and south.
The phenomena of most concern to deep water operators in the Gulf of Mexico

are surfaceintensified currents associated with the loop current, loop current
eddies, and other eddies (both anticyclonic and cyclonic). While reliable

information is available regarding the general speed distributions, translation

speeds, sizes and shapes of these currents, the details of the velocity distributions

and their variability are not well known.

The wind effect on an offshore structure becomes important when the

superstructure (portion above the MWL) is significant. The wind generally has two

effects - one from the mean speed and the other from the fluctuation about this

mean value. The mean speed is generally treated as a steady load on the offshore

structure. For a fixed structure, it is only the mean speed that is taken into account.

The effect of the fluctuation of wind about the mean value has a little effect on the

fixed structure. However, this is not the case for a floating structure. In this case,

the dynamic wind effect may be significant and may not be ignored. It should be
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