TravelTimes/SeaTravel

Rules

I have finished my research into sailing and boats. Might I say, wow! This is an incredibly complex topic. The physics defy a simple realistic model. There are too many variables involved. So as per my above posts, I have gone with a semi-realistic model.

For my research into sailing and boating, I used The Complete Beginners Guide to Sailing by Drummond, and Speed Sailing by Jobson & Toppa. I also used many web sites, such as www.sailnet.com. The info on Triremes comes from history buffs home pages (too long to list), as well as a project to build a recreation of a trireme over at http://www.atm.ox.ac.uk/rowing/trireme/ . I used Columbus' voyages, as well as Magellan's for historical significance.

I have designed two models. One is simpler and easier to figure. The other takes more into account of the boats speed rating. I have made certain assumptions about Exalted sailing vessels, per Savage Seas. They are not supposed to be especially efficient when it comes to catching wind. They do not heel in the wind (heeling is when your boat tips to one side while reaching or running. It allows for greater speed in many situations.) Like real world vessels, they like a gentle breeze best. In a gale, they are only doubling in speed from a gentle breeze, due to reefing sails. All this is found on pages 24-26. This uses the Beaufort Wind Force Model, found on pg 26 of Savage Seas.

Model 1:

First figure out your ships speed rating. Next figure the Wits + Sail of the person in charge. Have that player roll Wits+Sail. Add in the ships speed rating as auto successes. Each success is 5% efficiency of wind strength. Then add 10% as a baseline speed. Finally, consult the chart below.

For example: Dera is the captain of a Blue Water Merchant. She is sailing in a gentle breeze going 8 knots. Her Wits + Sail is 6. Her player rolls 5 successes. Her ships speed rating is 3. 5 + 3 = 8. (8 X 5%) + 10% = 50%. 50% is less than the maximum efficiency of 60%, so her speed is 4 knots. Example 2: Dera is trying to sail in a gale going 40 knots. She rolls 6 successes. 6 + 3 = 9. (9 X 5%) + 10% = 55%. Unfortunately, she can only go 35% at wind force 8. So she is sailing at 14 knots, and having to make Wits + Sail rolls as detailed in Savage Seas, pg 25

Wind Force             Max. Efficiency
1   (1-3 knots)          40%
2   (4-6 knots)          50%
3   (7-10 knots)         60%
4   (11-16 knots)        55%
5   (17-21 knots)        50%
6   (22-27 knots)        45%
7   (28-33 knots)        40%
8   (34-40 knots)        35%
9   (41-47 knots)        30%
10  (48-55 knots)        20%
11  (56-63 knots)        15%
12  (64+  knots)         10%

Model 2:

The second model is very similar to the first. There are 3 differences:

1. The ship has a maximum speed, equal to the speed rating X 3. This in knots. Thus a Small Coaster cannot go over 9 knots per hour.

2. The ST can increase difficulty if you need to tack into the wind. For example, if you are trying to flee the Lintha pirates and you need to beat into the wind, your ST could increase the "base difficulty" by 3-4 on your Wits + Sail roll.

3. The sail boat's speed rating determines Maximum Efficiency. See the table below:

Wind Force             Max. Efficiency
1   (1-3 knots)          10% + (Speed rating X 10%)
2   (4-6 knots)          20% + (Speed rating X 10%)
3   (7-10 knots          30% + (Speed rating X 10%)
4   (11-16 knots)        25% + (Speed rating X 10%)
5   (17-21 knots)        20% + (Speed rating X 10%)
6   (22-27 knots)        15% + (Speed rating X 10%)
7   (28-33 knots)        10% + (Speed rating X 10%)
8   (34-40 knots)        5%  + (Speed rating X 10%)
9   (41-47 knots)              (Speed rating X 10%)
10  (48-55 knots)              (Speed rating X 10%) - 5% 
11  (56-63 knots)              (Speed rating X 10%) - 10%
12  (64+  knots)               (Speed rating X 10%) - 20%

So for example, Dera from the examples in Model 1 is trying to outrun the Lintha Pirates. She is in a Blue Water Merchant. She is trying to head directly away from Bluehaven, but the winds are not cooperating. She has to beat into the wind (12 knots) to escape. The ST assigns a base difficulty of 3. Dera's player rolls 4 successes. 4 - 3 = 1 net success. 1 + 3 (speed rating ) = 4. (4 X 5%) + 10% = 30%. This is less than the Maximum Efficiency of 55%, so her net speed is 4 knots. Unfortunately the Lintha Pirates are in a Fast Courier, with a Water Aspect at the Helm. He is assessed an increased difficulty of 2 (Fast Couriers can tack closer into the wind). The ST rolls 6 successes for him out of a Wits + Sail of 9. 6 - 2 = 4. 4 + 5 = 9. (9 X 5%) + 10% =55%. This is easily below the Max Eff. of 75%, so his net speed is 6.6 knots. Time to get out the old daiklave. Example 2: Dera has killed the Lintha DB and stolen his ship. The Lintha God Blooded in the Bireme has called up a Hurricane to sink her to the bottom. Dera at this point is running straight from the wind. She rolls 9 successes (call it desperation). 9 + 5 = 13. (13 X 5%) +10% = 75%. Unfortunately, in a Hurricane going 80 knots, her Max Efficiency is 30%. So her speed should be 24 knots. However, this is over her Maximum Speed of 15 knots. So she manages to survive the storm with a few broken spars and a broken mast. She has still outpaced the Bireme by quite a bit.

On Triremes & Biremes:

Triremes are powered mainly by rowers. Most historians agree on a rate of 7 knots for a crew rowing for distance. In battle, to properly use the ram they would accelerate to 10 knots. Biremes do not have as much speed, but they are not as heavily covered. So figure 5 knots traveling, 8 knots maximum.

Summaries

And here is the summaries for ships:

Under sail, the amount covered in a day is obviously proportional to the amount of wind. The stats I am using depend on these assumptions: 24 hour sailing time (i.e. no putting into port at night. Halve this amount of miles if you are dropping anchor every night). In a gale, speed is only doubled. I am using Columbus and Magellan's averages for an average 3 dot speed sailing vessel. Please note that everything is in nautical miles. For those wanting conversion multiply the mileage by 1.15.

Speed     Average miles         Wind Speed
1 dot     74 miles / 24 hours   Gentle Breeze (8 knots)
2 dot     85 miles / 24 hours   Gentle Breeze (8 knots)
3 dot    100 miles / 24 hours   Gentle Breeze (8 knots)
4 dot    112 miles / 24 hours   Gentle Breeze (8 knots)
5 dot    130 miles / 24 hours   Gentle Breeze (8 knots)
1 dot    150 miles / 24 hours   Gale (32 knots)
2 dot    170 miles / 24 hours   Gale (32 knots)
3 dot    200 miles / 24 hours   Gale (32 knots)
4 dot    230 miles / 24 hours   Gale (32 knots)
5 dot    260 miles / 24 hours   Gale (32 knots)

This covers everything except for Triremes and Biremes. Now an ancient Triremes average "travel" speed was 7 knots. Under normal circumstances you cannot work a crew for 24 hours. So I figured work the crews for 12 hours, then sail for the rest. That gives us:

Ship    Average miles         Wind Speed 
Bireme  108 miles / 24 hours  Gentle Breeze (8 knots)
Trireme 132 miles / 24 hours  Gentle Breeze (8 knots)

Needless to say, they do not row during a gale. Use the wind, eh? Now this assumes a regular crew of rowers. If you are using the dead or Fair Folk leavings, realise that you can use the "combat speed", which for Triremes is 10 knots and Biremes is 8.5 knots. So a Trireme staffed by zombies can cover 240 miles a day on average.