First off how many cells of the submarine battery do you have were they from a military sub or civilian typical Navy subs had 2 batteries consisting of 126 cells in each battery compartment. a single cell weighed around 1600 lbs 54" tall by 15 x 21" most likely made by Exide Technologies or Gould Electronics, Inc.
Here is an article from the Australian Submarine Corp. the batteries may be a little different than those from a US sub but the science will be valid
http://homepages.mcs.vuw.ac.nz/~markm/preprints/SubBatteriesReport.pdf The reason for asking how many cells you have is to determine how you would need to connect them to your inverter for instance is you have a typical 12v DC nominal to 120 VAC inverter you would connect the cells in groups of 6 cells in series then parallel those groups together A 24v DC input inverter would mean 12 cells in series and respectfully a 48 VDC input would mean 24 cells in series
If you were to have a full compliment of 126 cells and connected all of them in series you could have almost 350 VDC output at full charge and close to 7,000 amps of current
If these are the smaller cells from a small civilian submersible they could be almost anything from L16 s on up
depending is the sub was a manned or un manned machine