I am currently in the market for one also. I've been looking at the Cabelas 270 model. It supposedly is manufactured by Standard Horizon for Cabelas. It seems to appear identical to the S.H. 270 model. Its currently on sale for $89 ($10 off). It is JIS 7 rated
FYI
from
http://www.opticsplanet.net/water-proof.html
Grade 7
Protected against the effects of temporary immersion in water.
Ingress of water in quantities causing harmful effects shall not be possible when the enclosure is temporarily immersed in water under standardised conditions of pressure and time.
Test conditions for Grade 7: temporary immersion between 0.15m and 1m
The test is made by completely immersing the enclosure in water in its service position as specified by the manufacturer so that the following conditions are satisfied:
a) the lowest point of enclosures with a height less than 850mm is located 1000mm below the surface of the water;
b) the highest point of enclosures with a height equal to or greater than 850mm is located 150mm below the surface of the water;
c) the duration of the test is 30min;
d) the water temperature does not differ from that of the equipment by more than 5 degrees Kelvin. However, a modified requirement may be specified in the relevant product standard if the tests are to be made when the equipment is energised and/or its parts in motion.
Summary of test conditions for Grade 7:
Test means: Immersion tank. Water level on enclosure: 0.15m above top, 1m above bottom.
Water flow rate: not applicable.
Duration of test: 30 minutes.