Depends on the starting penalty. If black, Z,  or U flag then the windward mark must be in position at the 1 minute signal in order to meet requirements  of rule 30.2, 30.3 or 30.4. If no starting penalty ( P flag) or I flag then there is no requirement in the RRS to have any marks in place at the start of the race. However it is good practice to have the 1st mark laid at the 1 minute signal 

As illogical as it may sound, the only rule that references when a mark shall be in place prior to the start of a race references the starting line (RRS 27.2).  So, if your question pertains to when marks need to be in the water prior to the start or after the start, there is none - until a boat needs the mark to sail the course. 

I assume that your reference to RRS 34 (Mark Missing; Race Committee Absent) was meant to reference RRS 33 (Changing the Next Leg of the Course).  RRS 33 states that "The next mark need not be in position at that time."

Although, there is no rule that requires a mark to be in position at a specific time - there is certainly something between common sense and best practices.  It does not make sense to not have the marks in the water prior to the warning, but - the rule provides you some flexibility, perhaps you are running late, and you can set the starting line in accordance with RRS 27.1, but your windward mark set boat needs a few minutes to get into position.  You probably included in your sailing instructions that the mark would be at a specified bearing and distance, if not, you probably will in the future.  The fleet will at least know the general proximity to where you plan to set the mark.  This lack of a rule gives you some time to get the mark in place before you confuse the fleet to the point that you become the topic of conversation back at the dock and not the event.

There is no rule that state when the windward and other rounding marks must be in position.  However, you must have a good reason for a delayed deployment which should not affect the boats or you'll spend some of your free time in the jury room.    

RRS 34 is about a mark missing and has no reference to the starting signal.

Delaying the deployment until boats are at the theoretical lay-in is in my opinion much too late.  

Good question.  We draw a distinction between club-level events and regional/national racing.  For club events, we recommend that the marks be in place before the warning signal.  That way, everyone can get comfortable with the course in plenty of time to sail it.  For regional/national events, we suggest that a) the SIs indicate that RC will display the compass bearing to the first mark before the warning signal; and b) the weather mark(s) be in place before boats are one-third of the way up the course.  In other words, nowhere near a lay line.  For ILCA and other dinghies, that usually means less than 4 minutes after the start.

As Luigi (Peter Reggio) would say, "The mark needs to be set before they (the competitors) need it."  There is no rule that requires it to be set at the start - even 30.3 or 30.4.

As long as it's in the general vicinity - unanchored - at the start, you're free to tweak the distance a bit, aiming for that perfect target time.  However, there is a measure of common sense involved and how much of your free time you're willing to donate to the jury in a redress hearing.

Also, the longer you wait to set the mark, the more likely it is that the anchor line will get wrapped on the mark vessel's propeller.  It's the Murphy's Law probability function.

Though there is no rule covering your question, if it is a frequent local occurrence to set the mark late, a mention of this in the Sailing Instructions is good practice - or at the competitors' meeting if a known situation exists.

62.1 does come into play.....

Having a mark not in position by the time a competitor needs it is an omission of the race committee.  So the lay line is too late, as, by definition, the mark has to be set to know where that is, and assuming that a competitor sees the mark boat drop it and knows to tack, that's not helpful.

In the vicinity of the right area, and with competitors knowing range and bearing, is good practice, and tweaks early up the beat are probably fine. but as you've had to give range then it's not feasible to make large changes to the distance anyway.  At some point well before laylines, competitors are looking for the actual mark and deciding on tacks and current and tide and tactics.....  To avoid redress hearings and potentially losing a whole race, I'd be aiming for the 1 min mark, and content if it was around start time but not much after.

Thanks all for your valuable comments.

A couple of points for clarification:
* The original post should have referenced Rule 33, not Rule 34
* Our lake is strongly influenced by thermic activity and has very variable wind, both in strength and direction. As such, it's not reasonable to publish a compass course before the start.
* Our lake is also rather deep (more than 200m in places), so we've started using robo-bouys, which can be moved far more quickly, via remote signal.

From the comments above, the timing for having the first mark set is not defined and we can debate whether good practice is before/during/after the start sequence.

Given the above discussion, a couple of other thoughts:
* The second (leeward) mark doesn't have to be in place at the start signal either and may be moved into position up until the first boat rounds the first (windward) mark (or perhaps even a little later, depending on your definition of good practice).
* Once a mark's position has been set, if it has to be rounded a second time (like our usual up-down-up-down-finish course), changes to the marks' positions are covered by Rule 33. On this topic, there have been discussions about including a statement in the SIs, that marks may be moved up to 100m without needing to signal the fleet.

It is common in the UK for SI’s to include a change that allows minor mark moves without signalling. For example “Mark moves of less then 100 metres may be made without signalling the change. This changes RRS 33.”

Jamie, do you mean to say that sailors typically start the race without a mark in place AND without a compass bearing and distance to the mark? And furthermore that at the start, the RC does not know where the mark will settle, BUT that it is already in the water?

I believe this would be atypical and outside of best practices. Deciding where the mark will be (macro-scale) after racers have begun sailing the course leaves a lot of room for potential favoritism. Imagine if three buoys were in the water, and halfway up the leg the RC announced (magically audible to all) which would be the one true mark. Could strongly advantage some racers over others. That's akin to the scenario I've suggested you are describing (and maybe I'm wrong).  Depending on line length relative to upwind leg length, which end of the line to start at could have a large role in winning the race. 

If the NOR clearly states this intention, then I guess it could be OK, but it is a very different kind of racing. Typical sailboat racing is to a mark, not to an eventual upwind direction. The sailor reads the wind (present and future) to reach the right place ASAP.

--

To actually answer the question asked, my experience as RC, coach, judge, and racing for 30 years suggests that marks are typically in place by the Prep signal. When they are not, the location is described on the course board. Sure, there is room for a percentage change (<5%? drift, small correction, etc.) over a long leg.

There are also some rules which may or may not suggest our answer, though none prescribe it directly:

My apologies if I've mis-represented or overstated the original situation.
I guess thinking from an outsider's perspective, how do you make it fair (or at least fun) for someone showing up for the first time is the primary goal. There shouldn't be any secrets or inside info; important if we want to build the sport.

What is wrong with having the top mark boat in position, telling the boats that it will be placed at bearing of xxx degrees at x.x nm.  Once a clean start is off have the top mark boat drop the mark, followed by the offset.  I do it a lot of the time and have had no complaints.  This only works with competent mark boats   

Sue, I think that works well.

I believe that OP suggested -- in a second post -- a start without a compass bearing, and the robo-mark is already in the water, but still moving (see screenshot below):

I still think this can work with the right "attitude" (ie. NOR language), but personally, I'd want to know about that before I toted my boat somewhere and paid an entry fee.

Sue,
If the boat is there and the mark is ready, why not drop it?

From what I have read, if you are using a robot mark, it is in the water during the start sequence and presumably you have signalled or otherwise designated the course by the warning signal. I don’t think you can move the mark. 

Moving a robot mark is different to laying a mark from a mark set boat and given RRS33 only allows for changes of course from a rounding mark (not a start line) there is no mechanism in the rules for changing the position of mark 1 after the warning signal if it is laid as you have signalled or designated at the warning signal that you shall sail from the start line to mark 1. 

I’m sure you could write an SI to allow you to move it while boats are sailing towards it but as a competitor, I am not sure how much I like the idea of a moving target. 

As I say, I think this is different to having a mark sat in a boat, if it’s not laid, it’s not moved.