In looking at the skill lists for all the types of lore I am noticing that there is no lore skill for the Imperial Navy and Scholastic lore Imperial Navy in the main book. As it shouldn't take much to figure out what these skills should cover with the examples of all the other types of lore that are out there. I am wondering what a guess of what the experience cost would likely to be. The same cost and level availablity as the lore skills for the Imperial Guard? Or a bit more experience depending on the circumstance and background of the characters?

I would probably charge the skill at 100xp more than the cost of a similar lore for the character purchasing it. Only a career directly involved in the Navy or a character background that links in sufficiently should really have the skill for anything lower.

Its a good idea though, theres a few others I can think of too, but the need for them has never arrisen.

A Navy lore, which would be the equivalent of the Imperial Guard Lore, should not cost any more than the IG lore. The premium comes in spending your XP to buy the Skill. IG spend a good amount of time on board Navy ships in transit so there is no reason why they wouldn't be able to pick it up.

I would allow it at the same cost and time as any IG lore on any class list.