WEMo is here:
NCCOS | Download the Wave Exposure Model (WEMo)
It does not look like it has been updated since 9.x.
Here's an old archived thread from the proto-GeoNet with some details. It's my opinion that even if you solved this problem as described in this thread you would be likely to run into ArcObjects incompatibilities with 10.x that would require more coding.
How do I check out a Spatial Analyst licence wi... | GeoNet Preview
I honestly think the best approach would be to find a spare machine and install ArcGIS 9.3 on it. Getting your hands on that may be difficult however (unless you have one around) because 9.x has been in retired status almost four years.