Problem about bathy extract.m of romsmatlab tools

[leon]

I did as arango said here(viewtopic.php?f=3&t=45&p=70&hilit=bath& ... 299d07#p70).Then I use the seagrid to caculate the depth and mask of the gird area. But I think the result of depth is actually wrong. My area is
24N-41N 117E-131E. The related is below:


I want to know is there something wrong with me or the seagrid or the bathy extract?

You are kind to give me some using suggestion.

Thank you