Maybe it’s the approach of Spring, maybe it’s a quasi-nautical tangent in the game I play in: I’ve been thinking about the Sandbox at sea (edit: I’m not alone, right, James?). My table-making tendencies are in high gear. But before I start in with tables and minigames, some easier observations:
Remember In Praise of the 6-Mile Hex? A hex with a height of six miles has side and diagonal lengths that are close enough to 3.5 and 7 to make calculation easy, and it breaks down into subhexes… well, it’s in the link.
If you “zoom out” at the proportions discussed there, you’re at hexes with a height of 72 miles. A 72 mile hex has sides approximately 42 miles long, and a diagonal just over 83 miles (call it 84! It’s not modern mapping!). Still fairly easy to calculate against, and has a bonus for ocean hex crawling: Large sailing ships, galleys, and sail boats cover 72 miles in a day. Small sailing ships are a bit faster (90 miles, a hair over the diagonal), but still fit pretty nicely.
Neat! It also means that my wilderness mapping hex paper- about 24 hexes long- covers more than 2M square miles. This is big enough to map a sea the size of the Caribbean and then some. When I drop down to the 6 mile scale, I can map two hexes from the larger map- enough to get several medium islands, like Jamaica, or half a large one.
But I can also use the fact that many smaller islands are less than 6 miles, combined with the Cook/Marsh dictum of land being visible 24 miles at sea (thus requiring entering the hex), to not map smaller islands on the big map at all. I can plan a few volcanic isles, or atolls, or maybe even a transient island that surfaces for days at a time on the back of an ancient turtle, and use them as chance encounters at sea. I like the idea of sailing under the decorative scrolls on your map, and finding both sea serpents and uncharted ritual islands.
Charlatan
Eric Minton
maldoor
Greengoat
David Wellington
James Nostack
tavisallison
The Mule Abides 
One of the best campaigns I ever played in was a pirates game, mashing up GURPS Swashbucklers and Fantasy, and it played a lot like D&D on the ocean. We used Caribbean maps and did not really need to explore so much but the idea of a hex crawl on uncharted seas sounds swell.
Looking over a lot of old game material – official, semi-official, and non-official publications – I have found a vast range in what is considered functional distances in overland maps. It’s something, as moderns, we just don’t grasp very well… how much distance a horse, or a caravan, or a creature, can cover in an hour or a day. I don’t know if water travel is easier or harder — I imagine distance is less of an obstacle than attempting mimesis in navigation. Regardless, I appreciate your attention to real world comparison and detail. An island-hopping adventure setting can be fantastic – each island a different microcosm, with odd civilizations and ecologies.
@Naked Samurai: I agree, but I think that this is particularly aggravated by the difficulty in comparing different data points. So, for example, you could answer the question of how far you can travel in a day on foot by figuring that a 4 mile per hour pace isn’t bad, and that you could reasonably walk for 10 hours a day, which produces a 40 mile per day pace. The data that goes into that is reasonable–on a good road, you can walk 4 miles per hour pretty easily. And you can even (pretty easily) find examples of people maintaining that pace (or faster paces–go for 12 hours and hit 50 miles in a day!). But it’s still ridiculous as an overland pace, except maybe for a forced march or a small elite group traveling fast. And typically people doing that sort of pace aren’t carrying 50 pound packs, let alone carrying armor. If you instead assume one league per hour (now defined as 3 miles, but historically often shorter– perhaps 2.5 miles), since that was the historic “distance you can walk in an hour,” and then you assume that walking all day is hard work, and it would be hard to walk more than 6 or 7 hours, and make a camp, and cook some food, and not be dead tired so that you can do it again the next day… suddenly you’re looking at an estimate of 15 or 20 miles/day. Get rid of the good road (say a good modern road, or an old Roman road), and instead climb over and around hills, fording streams and making your way through woodlands, and 10 miles in a day starts looking pretty good.
So, ideally, a game covers different speeds–a normal pace, of maybe 10 or 15 miles per day, and an exhausting pace of double that, and maybe even a maximum pace that’s faster than that. But it’s still hard to calibrate those accurately, and it’s hard to cover all the variations satisfyingly.
A sea exploring game could be a ton of fun, and random encounters make more sense the large the hex is. I suspect that material and concepts could be cribbed from space games too.
Adam makes a good point about max possible speeds and actual speeds. Particularly when ships are rowed instead of sailing, the actual speed is going to be quite a bit lower than max speed. Average wind, and actual wind are important for sailing ships. It is not very heroic, but many rowed shis had to pull over and beach every night because they did not have the facilities to feed and care for the crew, and early ships were not all that strong either.
You also make a good point. I’ll return to this in a post yet-to-come about fictional bases, but I’m working from an assumed setting of sailing ships on open seas. Most of it certainly can be made to work with galleys or longships, but it’s not my principal frame of reference. There will be some variable rowing speed present in the form of hunting boats launched from a ship, but the scale there is small enough to handle in different terms.
I’m also trying to re-use existing rules when I can, so the matter of wind-speed variability will be addressed by a daily roll on the optional Water Movement Modification Chart (X64). It may lack in verisimilitude, but I think it’s a sufficient, gamist compromise.
Your point about space games is well taken, and I’ll admit that my irrational prejudices there have prevented me from really mining them for material. I’ll try to reconsider that.
I put the Aubrey/Maturin books (Master & Commander et al) on my personal Appedix N because they awakened me to a deep craving for nautical adventure which I’m glad to see the tide bringing in!
Delta’s Corsairs of Medero was extremely satisfing in many ways, not least the mix of OD&D’s surprisingly extensive naval rules + his Book of War mass combat + roleplaying shenanigans. The one thing it didn’t have was distance: we used the miles-scale hexmap just to decide where to patrol, and the next scale down was 1 inch equals 10 figures. His random encounter check basically determined whether or not you had an encounter that you could catch or couldn’t get out of missile range of, which is reasonable but left out a lot of O’Brian’s days-long stern chases and sailing through the night hoping to get a sight of the quarry’s sails at first light if you guessed the other captain’s course correctly. Having maps at the scale you describe here, and being ready to zoom down to six-miles or further as necessary, is a right step in that direction. I don’t know of any good rules to make these kinds of longrange naval maneuvering gameable, though.
I seem to recall that there is at least one OSR based space game, which would have exploring type information. Ah yes, Stars without Number, reviewed by Grognardiahere.
As for chasing down/eluding other ships, you could either do that as some sort of opposed skill check, or do it with role play to see if the tricks/counter tricks work out.
There are some abstract rules for evasion in Cook/Marsh (X64) and in LL. I think the question of gaming and specificity for that kind of mechanic depends on whether the players are captaining a vessel themselves, or are hired on as marines/harpooneers/etc. … but player interactivity is good in any case, and I love roll-offs. I have some half-baked ideas in that vein, but your suggestion re: skill checks definitely illuminates one issue with doing this in a B/X context.
Charlatan, let’s make this happen. What’s your availability in late February/early March? I think I’ll have my thing kind of drafted up and ready to go by then.
Let’s do it: I’ll get a thread going.
So I see you have this running now. I’m really interested to know how it works out and what the actual play challenges are. I’d also love to know how much the character of the ship gets developed through play. Most SF starcrawl games just struck me as ersatz seacrawls with fewer credible environmental hazards that could act as adventure hooks.
Also if you want resources or historical detail from global seafaring cultures, I’m finishing a thesis on it right now.