Hi Dan,

I certainly will share what I land on here..  Also In the Class-T vs ANL. The Class-T max out at 400A  (what you have and seems to be working).    
I chose ANL due that I can put one on at the the Amp rating that will match the bow thruster (thus my original question of this thread).  I guess I will find out if it blows!  It seems here there is not a write or wrong- but it is good to see others being safe as well.  
Here is a good guide I found to fuses, use, and sizes.
http://assets.bluesea.com/files/resources/reference/Quick_Guide_to_Blue_Sea_Systems_Fuses_and_Fuse_Holders.pdf