Most feats published by Paizo are considered legal for play, unless they are explicitly listed as banned. New feats available to characters in the Steamjammer setting are listed below.
Craft Spelljammer Helm (Item Creation)
You can create spelljammer helms, which grant spelljamming vessels their power.
Prerequisites: Caster level 12th, Craft Wondrous Item
Benefit: You can create and repair spelljammer helm whose prerequisites you meet. Crafting a spelljammer helm takes 1 day for each 1,000 gp in its price. To create a spelljammer helm, you must use up raw materials costing half of its base price. You can also mend a broken spelljammer helm if it is one that you could make. Doing so costs half the raw materials and half the time it would take to craft that item.
Spelljammer Helm Operation (General)
You can operate a standard spelljammer helm proficiently
Prerequisites: Caster level 1st
Benefit: Pilot becomes a class skill for you.
Normal: Without this feat, Pilot is a cross-class skill.
Spelljammer Specialization (General)
Choose one type of spelljamming vessel; you are especially good at piloting that type of ship.
Prerequisites: Spelljammer Helm Operation, Pilot 4 ranks
Benefit: You gain a +4 bonus to all pilot checks made when operating your chosen ship.
Special: This feat can be taken multiple times. Its effects do not stack. Each time you take this feat, it applies to a new type of spelljamming vessel.