Looking to finally get into airships and submersibles seriously and have been looking over the threads and can't seem to find a good answer to this.

My Submersible is still using all Shark parts and is level 62. I'm looking to upgrade it and build additional subs and I know I can't just max out everything. What is a good or at least passable build for unlocking all of the sectors? I know RNG is involved as well.