humming bird

[cobalt]

so when i read iron coffins, i remember in a few instances herbert werner mentioning that under long dc attacks, the boat would slowly sink until they had to blow a little compressed air out and rise them up a little again. in nygm the boat sinks at 0 knots, is there anyway to modify the file nygm changes so that it will sink slowly at say, maybe 2 knots? does it have to do with the weight of the boat?

thanks in advance