Estimating Distances

[Sjark]

I have a party who are at a point of high elevation. They see an object in the far distance that they want to get to. One party member wants to cast a spell that lasts for one hour when he thinks he is one hour away from the location.
The question is, how does he know when he is at the proper distance? From the mountain, he can landmark a certain location, but what should his estimation of time/distance be? Should he roll a Knowledge check? Survival? Straight intelligence?
My apologies if this is already covered in the CRB, but I couldn't find anything. Any help or suggestions would be appreciated, preferably if it can be extrapolated based on the rules (ie, give a reference if possible).

Thanks!

[Bronnwynn]

I've always run it as players simply intrinsically knowing distances. Makes life much easier. At that sort of scale, it's a bit different, and I might call for a check if he wants to be precise about it.

[dragonhunterq]

There's nothing in the rules that I could see.
Survival seems the best fit, maybe with result based on whether they want to get there with the spell still up/as close to it's expiry as possible:
DC30 optimal timing.
DC25 75% duration they aimed for/spell elapses 5 rounds early
DC20 50% duration/1 minute early
DC15 25% duration/5 minutes early
DC10 10% duration/10 minutes early

tweak as desired

[LazarX]

It's a pretty hard thing to do for the following reasons.

1. Lack of rangefinder tools and the biggie...

2. Lack of any means to tell time to that level of precision.

DC 30 Survival seems appropriate.

[Sjark]

dragonhunterq wrote:

There's nothing in the rules that I could see.

Survival seems the best fit, maybe with result based on whether they want to get there with the spell still up/as close to it's expiry as possible:
DC30 optimal timing.
DC25 75% duration they aimed for/spell elapses 5 rounds early
DC20 50% duration/1 minute early
DC15 25% duration/5 minutes early
DC10 10% duration/10 minutes early

tweak as desired

Seems like a decent solution, thanks!

[Korlos]

If the PC wants the spell active when they arrive, he could estimate when they are 30 minutes away and have fudge room.

I would do something like this:
DC 9 or less: You are confident you can get there before sundown
DC10: You think it is 4-7 miles. 2-3.5 hours to travel
DC15: 5 or 6 miles. 2.5-3 hours.
DC20: As DC15, but you spot a terrain feature to path around (save time or reduce encounter chance)
DC25: As DC20, plus you spy a convenient landmark to time your spellcasting by