Boat Challenge

[Catullus64]

I would like to pick some brains for a sequence I need to run this Tuesday, involving navigating a boat through treacherous waters.

The three player characters and two NPCs, having stolen a longship from some Vikings, are undertaking a voyage under close time constraints to the mysterious isles of Orkney. They've been told of a water passage in the Hebrides through which a mystical current runs, which would allow them to traverse several hundred miles in just a few hours.

What I've established:

• The strait has a swift-moving current, and many twists and bends.
• The water is surprisingly warm for the climate (a fictionalized twist on the gulf stream).
• Plants and animals found nowhere else in Europe grow along the coast here.
• Illusory visions in the water and voices on the air are a common experience for sailors in the strait.

The characters:

• Two NPC warriors, both strong and agile but neither experienced seamen.
• PC Warrior and Cleric, both of whom have undertaken minor sea voyages before but are not sailors. The Cleric can walk on water.
• PC Selkie, able to turn at will into a seal and communicate with marine life.
• The tone of the game leans towards mythic fantasy, so one or two heroic figures rowing an entire longship is not out of the possibility.

Possibly relevant system information:

• My homebrew system is a dice pool game, with pools of d6 and successes counted on rolls of 5 or 6.
• There are ten ability scores: Attack, Defense, Strength, Speed, Constitution, Dexterity, Intelligence, Perception, Willpower, Charisma
• The normal combat initiative system is thus: all players and player-allied NPCs roll Speed test, contested by the highest-Speed enemy. Those who beat this test act before the enemies in whatever order they choose, those who fail act after the enemy in whatever order they choose.
• Characters can take two action on their turn, and cannot take the same action twice except for Move/Escape.

My current plan is to use the combat initiative system for this skill challenge, but I'm open to alternate suggestions. How would you make a memorable encounter based on these constraints?

[Unoriginal]

I would like to pick some brains for a sequence I need to run this Tuesday, involving navigating a boat through treacherous waters.

The three player characters and two NPCs, having stolen a longship from some Vikings, are undertaking a voyage under close time constraints to the mysterious isles of Orkney. They've been told of a water passage in the Hebrides through which a mystical current runs, which would allow them to traverse several hundred miles in just a few hours.

[...]

• My homebrew system is a dice pool game, with pools of d6 and successes counted on rolls of 5 or 6.
• There are ten ability scores: Attack, Defense, Strength, Speed, Constitution, Dexterity, Intelligence, Perception, Willpower, Charisma
• The normal combat initiative system is thus: all players and player-allied NPCs roll Speed test, contested by the highest-Speed enemy. Those who beat this test act before the enemies in whatever order they choose, those who fail act after the enemy in whatever order they choose.
• Characters can take two action on their turn, and cannot take the same action twice except for Move/Escape.

My current plan is to use the combat initiative system for this skill challenge, but I'm open to alternate suggestions. How would you make a memorable encounter based on these constraints?

If the current is strong, then the longship is moving regardless of what the PCs are doing, and they must use the oars to direct it safely. To me this would be represented by a Strength check where the group as a whole must get a certain number of success, or the longship takes damage.

Each section of the strait would have different numbers of success required, based on how difficult it is to sail through it.

Having at least one person do Perception checks vs the illusory and treacherous strait hazard could reduce the number of success needed for a given section.

The Strength and Perception checks would take two actions to do. Making it possible to do it as one action but with an increased difficulty could be good (ex: two less successes are counted for this character).

Given the mythic fantasy tone of the game, I think this area would be perfect for an Old Man of the Sea encounter.

Maybe sailors or pirates nearby have been abusing the power of the strait, so the Old Man of the Sea (a spirit/minor sea god) has decided to prevent them from using it anymore, and since the PCs have stolen a Viking ship the Old Man has mistaken them for those who would abuse the power too.

So when the longship approaches, before it gets caught in the current, the PCs hear an aged voice, louder than the rumbles of the water, shouting at them to turn back, as the strait is forbidden for all who would make ill uses of its powers. If the PCs continue, once they have crossed the first section of the strait (and so have understood the mechanics to keep the ship from crashing), this old coot with sun-burned skin and wild, sea foam white beard & hair jumps on the deck of the ship, then proceed to fight them with unarmed attacks, improvised weapons like oars, wooden debris and other clutter you can find on a ship, as well as wrestling moves.

If the Old Man gets into the water (either as a result of being pushed, dragging a PC there or being made to follow one of them), he turns into all kind of sea creatures at will, be it fishes, sea mammals, mollusks, etc, in order to gain an advantage in the situation that's happening when he changes.

The Old Man's goal wouldn't be to kill the heroes, just stop them from crossing/get their ship wrecked so they won't try again. He will rescue them if they're in danger of dying, unless they do something to put him in an irrational rage, at which point all gloves are off until he manages to calm down.

The way I would run this encounter, there are four main ways it could end:

- The heroes's ship is destroyed, which leaves the Old Man more ready to talk things out. If they convince him they weren't a threat then, he'll feel bad and will help them find a replacement (plus maybe some additional perks)

- The heroes manage to convince the Old Man they're no threat during the fight, at which point he'll stop attacking and help them cross safely (and maybe give more perks if they can befriend him)

- The heroes manage to both fight the Old Man and cross the strait safely. The Old Man is sad to have failed, but admit the heroes' triumph is fair and square. The PCs can then try to convince him they weren't a threat (or try again, if they didn't manage to do it during the fight), at which point the Old Man is terribly sorry and compensate them for their troubles with an appropriate sea-themed boon

- The heroes manage to fight the Old Man off well enough he retreats. He lingers long enough (but our of their reach) to congratulate them as mighty adversaries and worthy opponents even if they're evil pirates (or other group who have lost their strait pass due to their behavior). If the PCs convince him *then* that they weren't threats, the Old man, like in the other options, apologizes profusely and compensate them for their troubles/reward them for being great combatants even in a hard-to-navigate part of the sea.

[Lord Torath]

Be prepared for the PCs to fail their ship control checks. What will failure look like?

When I ran a brief ocean-crossing adventure, sinking the ship was never an option. I mean, the PCs could have done that if they really wanted to, and I'd have let them succeed, but there were no ship-sinking threats they could lose to, that I would then have to fudge if they failed their checks to keep it afloat.