Kobune Captain [Bushi] (Emerald Empire p143)

The majority of the Mantis Clan's holdings are removed from the mainland by a vast expanse of sea, resting amid the Islands of Silk and Spice. The clan has lived this way for one thousand years; although the ascension of the Mantis to Great Clan status resulted in the addition of small mainland provinces held by the Tsuruchi and Moshi (and later the Kitsune), the lifeblood of the Yoritomo family still flows through the fleets of kobune that ferry materials and personnel back and forth to the mainland. The captains of these vessels are the trusted servants of the Mantis Clan Champion, and are responsible for ensuring their clan endures and prospers in spite of the perpetual threats they face from enemies, pirates, weather, and any other number of other hazards. Young samurai look upon these masters of the wave as an inspiration, admiring them for their bravery, their reputation, and their wealth. If some are possessed by the stereotypical arrogance of the Yoritomo family, it is at least well deserved, for they are surely the true sons and daughters of the clan founder Kaimetsu-uo and the chief bearers of his legacy in the modern Empire.

Requirements:

Rings/Traits: Water 3
Skills: Commerce 4, Knives 3, Sailing 4
Other: Must possess the Leadership Advantage, and have been appointed to a position of command within the Mantis Clan
Techniques

Rank 1: The Joy of Plunder
The promotion to the rank of captain in the Mantis navy is one that comes with considerable benefit and reputation. Your Status Rank is considered one higher when interacting with all members of the Mantis Clan and with any merchants from the heimin caste. When you spend a Void Point to augment any Merchant Skill, you gain +2k2 instead of +1k1. Once per month you may make a Commerce / Intelligence Roll (TN 25) and gain an amount of koku equal to the amount by which your roll exceeds the TN.

Rank 2: Strength of the Mantis
The true measure of a captain is the quality of those who pledge their loyalty to him. You gain 30 Experience Points which may only be used to purchase the Servants Advantage. The servants purchased in this manner represent a portion of your crew. Budoka servants purchased in this manner are instead considered to be Rank 1 Yoritomo Bushi. You may also spend 10 points to gain a Rank 1 Moshi Shugenja as your navigator. The shugenja is considered to have Air 3 rather than all Rings at 2.

Rank 3: Master of the Seas
A true captain of the Mantis Clan excels in all areas pertaining to his duties. You may spend a Void Point on any Merchant Skill Roll (excluding Craft Skills) to replace the normal amount you would roll with 10k10. You may also add a bonus of +3k0 to all Bugei Skill Rolls made while onboard a water-borne vessel.

Storm Riders [Shugenja] (Core Rules p248)

The Storm Riders are the elite shugenja unit at the heart of the Mantis Clan's armadas. They devote all of their studies to the ocean and the water kami that flow around the Mantis islands. The Storm Riders are the undisputed masters of the sea, and they strive to maintain their connection to the waves at all times. The Storm Riders' value in naval combat is fearsome, a deadly threat to any who might challenge the Mantis Clan's dominance of the waters.

Requirements:

Rings/Traits: Air 3, Fire 3, Water 5
Skills: Lore: the Sea 5, Sailing 3, Spellcraft 3, Lore: Theology 3
Other: Elemental Blessing (Water) Advantage
Techniques

Rank 1: Strength of Suitengu
The Storm Riders are at home on the seas, navigating with an ease envied by all who see them. Your Shugenja School Rank is considered one higher for purposes of casting Water spells. You may spend a Void Point to release a lightning bolt from your hands as a Complex Action. This bolt strikes one target within a range of 10' x our Water Ring. It rolls and keeps a number of damage dice equal to your Air Ring. You may expend spell slots to increase the damage of this bolt by +1k0 per spell slot expended, up to a maximum of your Storm Rider Rank.

Rank 2: The Raging Ocean
The Storm Rider's connection to the ocean allows him to extend beyond his limits. Your Shugenja School Rank increases by one. You Water Ring is considered 2 ranks higher for purposes of determining the number of spells you may cast per day.

Rank 3: Child of Osano-Wo
The Storm Riders are the descendants of the Fortune of Fire and Thunder, and their blessings protect them from his domain. Your Shugenja School Rank is considered 1 higher for the purpose of casting Water spells. You may spend A Void Point as a Free Action to gain immunity to all spells possessing the Thunder keyword for 3 rounds. This ability only affects spells of Mastery Level 3 and lower.