Ship Mage
Matthew Hedges, mhedges@chariot.net.au

Class Level	Base Attack Bonus	Fort Save	Ref Save	Will Save	Special	Bonus Spells	
Spells	
1st	0	0	0	2	Sea Legs	Fog Cloud	+1 level of existing class	
2nd	1	0	0	3	Ocean's Harvest 1/day	Whispering Wind	+1 level of existing class	
3rd	1	1	1	3	Ocean's Fortitude	Flame Arrow		
4th	2	1	1	4	Ocean's Harvest 2/day	-	+1 level of existing class	
5th	2	1	1	4	Ship Rune	Gust of Wind	+1 level of existing class	
6th	3	2	2	5	Ocean's Harvest 3/day	Lightning Bolt		
7th	3	2	2	5	Ship Rune	Wind Wall	+1 level of existing class	
8th	4	2	2	6	Ocean's Harvest 4/day	-	+1 level of existing class	
9th	4	3	3	6	Shipmage's Shield	Ice Storm		
10th	5	3	3	7	Ship Shield	Chain Lightning	+1 level of existing class	

The pirate ship closed rapidly on the royal cog, both ships lurching in the swell. Men aboard each ship try to keep their footing as they aim their missile weapons at the crew on the opposing vessel. The slam of the light catapults firing signals the beginning of the fight. On the decks men rush about arming themselves for the inevitable boarding. Just then the captain of the pirate ship spots a slower moving figure on the forecastle of the royal ship. The figure begins making hand gestures and the pirate captain realises he has seen this before. "Mage!" he yells at the top of his voice, pointing a bony finger toward to mysterious figure on the opposing ship. The pirates begin to lose arrows at the figure, most hitting the wooden sides of the forecastle. Then one strikes the figure, and instantly disappears in a blue flash. The figure is still gesturing. The pirate captain yells again in desperation to his men "hit the mage!!", and again points to the figure on the forecastle. Volleys of arrows and bolts clatter around the figure, but it is too late. The figure has finished gesturing. With an ear-splitting crack a bolt of lightning smashes the mast of the pirate ship into splinters. As the sails and rigging fall in to the water, the pirate vessel slows, no longer able to catch the wind.
Ship mages are highly prized spell casters who focus their spell casting on the needs of a ship and it's crew. Usually reporting directly to the captain of a vessel, the Shipmage provides additional firepower in battle, and some control over the weather.
Larger vessels or wealthier captains may have more than one Shipmage. Certainly there are many apprentices, who are not yet true shipmages, and they serve their masters needs and receive training at the same time.
Captains usually seek spellcasters who can control the weather to some extent, and those who can add firepower in battle. Thus shipmages come from a variety of spell casting backgrounds. Sorcerers, with the greater number of spells cast per day, are very useful for combat, however they have a  limited spell repertoire. Additionally, since sorcerers are born not schooled, finding a steady supply of them willing to risks the hazards of the sea is very difficult. Wizards are easier to come by, and their congregation at arcane schools makes them somewhat easier to come by. Since junior wizards require training they can be lured into sea service with the prospect of very cheap training. Some bards have found themselves in service as shipmages, their music often providing a lift in the ship's darkest moments, and their ability to heal coming in very handy.
Navies (official and otherwise), pirates, merchant companies and adventurers are all known to employ ship mages on their vessels. The presence of a ship mage can often determine the outcome of a battle at sea, and thus they are much sought after.
Ship mages require good stamina and better physical hardiness than average wizards do.

Hit Die: d4
Requirements 
Knowledge (Seamanship): 5 ranks or
Profession (Sailor):  5 ranks 
Feats: Great Fortitude, Dodge
Spells: Must be able to cast of 3rd level arcane spells.
Special: Must serve as a Shipmage apprentice to a Ship mage for a period of at least four months sea-time. 
Class skills
The class skills (and key ability for each skill) of the Ship mage are Alchemy (Int), Balance (Dex), Climb (Str), Concentration (Con), Craft (Int), Intuit Direction (Wis), Knowledge (Seamanship) (Int), Knowledge (all skills) (Int), Profession (Shipmage)(Wis), Scry (Int), Spellcraft (Int), Swim (Str), Use Rope (Dex).

Skill points at each level: 2 + Int modifier
Class Features
Weapon and Armour Proficiency: Shipmages are not proficient any armours or shields. They are proficient with the following weapons: club, cutlass (scimitar), dagger, heavy and light crossbow, quarterstaff. Note that armour check penalties for armour heavier than leather apply to the skills Balance, Climb, Escape Artist, Hide, Jump, Move Silently, Pick Pocket and Tumble.
Sea Legs:  Used to steadying themselves on rolling decks, shipmages gain an +3 competence bonus on balance checks (made anyway). Additionally, due to their increased agility acquired from serving on a ship, they gain a +2 circumstance bonus to reflex saving throws made at sea.
Ocean's Fortitude:  The ship mage is a product of their harsh environment. They receive +3 bonus to fortitude saving throws while at sea.
Ocean's Harvest:  The Shipmage can conjure food and water as per the spell Create food and water, the number of times indicated.
Ship Rune:  The Shipmage can inscribe magical runes in the ship, which contain arcane power that can be called upon when fighting on the ship. Every time the Shipmage receives a new ship rune, they can select any metamagic feat. This can then be applied to any spell (the Shipmage does not have to select a particular spell) that the mage can already cast, but can only be used once per day, and only while onboard the ship. As such the metamagicked spell does not take up higher levels.
Shipmage's Shield:  Shipmages devote a great deal of time into researching spells to better protect themselves in battle at sea.  The Shipmage's permanent shield provides a constant protection from arrows spell for the Shipmage whenever they are onboard their ship (the mage only receives 10/+1 damage reduction).  This protection is facilitated by a ship rune, much like metamagic feats above. Note: If a Shipmage leaves one vessel permanently then the Ship runes will disappear magically, and the Shipmage is then free to inscribe replacement runes on a new vessel. If the ship is sunk but the Shipmage lives, they will not be able to inscribe new runes for a period equal to half the time that they served on that ship.
Ship Shield:  Allows a Protection from Arrows spell to affect the whole ship once per day. Treat as caster level of 15 except that the value of damage reduction is only 10/+1. This includes attacks on the ship's structure.
Bonus Spells:  The Shipmage receives the indicated arcane spell as a bonus spell castable once per day, only while onboard the ship. These spells are some of the most used spells by ship mages.
Design Note: To ensure that all can use this class, I have only used spells found in the PHB. However it is conceivable that more suitable spells could be found, especially those converted from the 2nd Edition such as found in Dragon magazine issue #235.
Spells:  The ship mage continues to acquire spells as per their original spell casting class.