Roger .. I'll take a quick go at it. 

Seems to me the phrasing of the above rule is clear ... can't rely upon the engine of "the other vessel".  If the argument is that the falling tide would have made her hopelessly grounded .. i can't see how she claims no advantage. 

Also, I don't think it's a DNF.  The RC shall shore her in her finish place.  IMO, it's  either she retires or the RC or another boat should protest her for breaking 43 as soon as that information is available.  

I agree, if a boat complies with the definition of finish then she gets a finishing place. 

Except for the usual, only a protest committee can make a boats score worse. 

On the redress matter, the boat could have protested, it did not, would it therefore be  partly her fault? So no redress? 
The rc made no act or ommission if they scored the finishing position, and protesting for them is discretionary, do no failure here. 

Assume there are three boats entered and 42.3i applies.  Is finishing third a significant advantage in the race over 4 points for DNF or RTD?

Tentatively: the RIB's engine is not equipment. It is equipment of another, external boat. It may not be availed of. 

The Race Committee correctly finished A third.

A did gain a significant advantage, namely, that of finishing third rather than finishing DNF. Rule 42.3 (i) does not apply.

It is discretionary for the RC to protest. Competitors, by contrast, are expected to follow and enforce the rules, and to take a penalty if aware of a breach (basic principles). B is aware that A grounded, as the facts are that B went past A while A was grounded and would have seen this. There is no information about when the protest time closes, but it seems to be a safe assumption that it is closed.

Therefore: A breached RRS 41. RRS 42.3 (h) does not apply. A gained a significant advantage by so doing. Even if it were her own engine, Rule 42.3 (i) would not apply. There is no exoneration under Rule 43. The RC were correct to finish A third, but A should have retired for the breach of RRS 41. The RC are not obliged to protest A for this, and it is not an improper omission for them not to protest. B could and should have protested A's failure to retire. B did not do so. If the protest time is still open, B should protest. If it is not open, the relative disadvantage is due to B's failure to protest. A gaining an advantage through B not protesting is not one of the grounds for redress under RRS 61.4 (b). B is not entitled to redress.

A received outside help that was not in the form of information or help for a crew member.  A broke RRS 41.

RRS 42.3(h)  refers to 'the other vessel', that is to say another vessel which a boat using propulsion collided with.  Using force applied by equipment of a RIB which A had not collided with is not permitted with respect to RRS 42.  The equipment of the RIB that applied force was it's engine:   that is a propulsion engine.  Using force applied by another vessel by means of it's propulsion engine us bit permitted with respect to RRS 42.  RRS 42.3(h) does not excuse A for receiving help from the RIB.

OP states that there was no SI permitting propulsion in accordance with RRS 42.3(i).  Whether or not A gained significant or any advantage is irrelevant to her breach of RRS 41.

If B had observed A being towed off the bank, she could have protested A.  Supposing that B did not come within hail of A around the time of the incident, B is not required to hail 'protest' or display a red flag, and her only obligation about her intention to protest is to inform A of her intention to protest at the first reasonable opportunity (RRS 60.2(b)).  Time for 'first reasonable opportunity runs from the time of B observing the incident

B did not protest A and if she had done so, seemingly, she did not inform A of her intention to protest so any protest would be invalid.

If B did protest A, she could contend that she observed a blatant rules breach and assumed that A had retired in accordance with Basic Principles Sportsmanship and the Rules, and only discovered to the contrary when the results were posted showing A scored in a place.  If B informed A of her intention to protest and delivered a written protest at the first reasonable opportunity after the results were posted, I would be inclined to accept that B had informed A at the first reasonable opportunity and also to extend the protest time limit so that B's protest was valid. I am aware of RYA Appeal 1999/1

 A boat that waits to see whether another boat will take a penalty before displaying a protest flag has not acted at the first reasonable opportunity.

In this case, If B had made a reasonable effort to get her protest in, I might remember that I am not in the UK, and might not undertake the argument by extension from that Appeal to declare B's protest invalid.

Hoooooowever, B has not protested A:  B has requested redress.

The grounds B advances for her entitlement to redress is an improper action by the race committee in scoring A in her place instead of DNF.

That is plainly wrong.  As Mike has said any boat that finishes cannot be scored DNF.

In accordance with RRS A5.1, a race committee can only penalise a boat without a hearing by scoring her other than in her finishing place by if she does not sail the course (including starting and finishing), ZFP, UFD, BFD or fails to provide a certificate in accordance with RRS 78.2, or the boat retires or takes a SCP.

None of those circumstances applies so the race committee cannot penalise A in any way.

IMHO A richly deserves to be penalised.  Is there some action that the race committee an take to achieve this?

Yes, the race committee may protest a boat (RRS 60.1).

For a race committee protest against A to be valid the race committee would need to inform A of it's intention to protest at the first reasonable opportunity.  Time for first reasonable opportunity woudl run from when the race committee received A's declaration.

If the race committee hasn't already protested A before B delivers her request for redress, then I think the race committee has missed the boat, an any protest from the race commitee against A will be invalid.

But is not protesting, or not validly protesting A an improper omission by the race committee?

Case 39 flatly says

A race committee is not required to protest a boat

The race committee is not itself empowered to penalise A, and is not obliged to protest A.

There is no improper action or omission by the race committee.

B has no grounds for an entitlement to redress.

Even if there was in improper action or omission by the race committee, B's own failure to validly protest A is fault of her own and this would disentitle her to redress.

In my opinion, A's declaration  that 'they accepted outside assistance on the grounds of safety but did not gain any advantage of place' is, to say the least disingenuous.

A mere glance at RRS 41 shows that gaining advantage is irrelevant to any breach of RRS 41. 

The assertion that there was no 'advantage of place' is, in my opinion highly unlikely.  A was fast aground on a falling tide. OP mentions that there was a race time limit.  I think that it is likely that if A had not been towed off, she would not have finished within the time limit and would have been scored worse than 3.

A's declaration in those terms looks very much like an attempt to throw dust in the eyes of the race committee. 

What the race committee could have done, on receipt of A's declaration was either

Not having done that, the race committee might, if it believed that A's declaration was intended to confuse or mislead the race committee, report the matter to the protest committee and request RRS 69 action:  If the race committee can convince the protest committee, then A can be brought into a RRS 69 hearing and penalised, without consideration of protest validity.

Was it a benign sheltered location, where the worst that could happen by waiting for the next tide was boredom, or would boat - and therefore crew - have been at risk if they hadn't got the boat off straightaway? But even then I think it's clear that if they hadn't had the assistance they would have been TLE or DFL, so they were clearly advantaged.

We've had similar discussions in the past about whether using an engine to get off the ground on a falling tide is 'safety' (and allowed) or 'gaining an advantage' and have been through various iterations.  We currently include in the instructions 'A boat that uses her engine to get clear after grounding shall stop using her engine as soon as she is clear, notify the use of her engine to the RO with her finish declaration, and accept without a hearing a penalty of 30 minutes added to her elapsed time.' (and cite applicable rules changed). Our thinking is that if she goes aground on a rising tide, 30 minutes is a big enough penalty that she would just wait for the tide to carry her off, but if she does it on a falling tide, she would feel able to use the engine and accept the penalty, which is sufficient that it other boats shouldn't feel agrieved.  But we didn't think of the engine being on another boat!

Absolutely it is.

In OP scenario it's the difference between first and last in the series.

1 place is usually regarded as significant, until we get down into the 30s, and even then we need to think about qualifiactions, rankings and placings in obscure sub-series.

Jim, you seem to be saying that <vessel at risk> = <vessel in danger> = <crew in danger>.

I don't think that holds up in general terms.

If there had been danger to crew, the wily writer of A's declaration would have said 'crew in danger RRS 41(a)' loud and long.

Do not really blame the boat, ok it did not retire, but it did report the assistance.

This was inappropriate  but i believe required under the old rules, you then awaited your fate after the rc reviewed it.

Ws has removed this, i am not saying whether this is right or wrong.

It is just keeping tinkering with the rules and leads to confusion.

Kirsteen, I think once your race committee decides to allow propulsion to get clear after grounding, you've opened the door and that's quite OK.

But your SI allowing use of a boat's own engine under RRS 42 has no effect on receiving help under RRS 41.

Very significant in the series but 42.3i says significant advantage in the race.  A place is not at stake, boat is last in any case.

Charles: score for 3rd place is 3, score for DNF is 4 (or greater if there are some entrants that did not sail).

And that's all the more significant because of it's effect on the pointscore.

MIke, I'm quite happy to blame the boat.

Unless we're talking about Jeanneau 55s, we're talking about boats with at least someone on board getting paid good money to race the boat who should know better than to put in a smart-alec declaration.

PS .. one more interesting thing on RRS 63.2(c) and Case 44.   

Though 63.2(c) uses the word "may" ('may change the type of case'), Case 44 uses the word "shall" (' the protest committee shall treat it accordingly'). So there are instances when the PC "shall" change the "type of case" from the type the boat filed. 

So, Boat B might use Case 44 to request a reopen and make the argument that the PC made a significant error (or the PC decides to themselves) in not treating his R4R as a protest. 

Ang, strongly disagree.  You can't morph a request for redress into a protest in any circumstances.

RRS 60.4(b)

A protest is invalid also if it is from a committee and is based on information from
(1) a request for redress,

And for a protest to be valid, the protestor has to inform the protestee of the intention to protest (RRS 60.2)

No one mentioned DSQ. Seems to me that A clearly accepted outside help that was advantageous, i.e. A finished the race with a good score. After grounding, 42.3 (h), a vessel may use any method OTHER than a propulsion engine, unless specifically permitted in the Sailing Instructions 42.3(i)..

Lot of talk about gaining an advantage, but where is this a feature of the rule, about being towed off by a rib?

Thank you all for your comments.

The incident occurred in a fast flowing river in Malaysia with more than 2m of ebb left. All parties viewed the help as complying with RRS 41(a) "help for a crew member who is ill, injured or in danger" as, even if the keel did not snap nor the boat swamp, it would have been after dark very close to a busy shipping lane by the time they could re-float.

The question then rested on whether A had infringed RRS 43.3(h)

The PC did not grant redress, they could not protest A themselves and neither the RC nor the competitors protested A within the time limit.

After a heated debate in the Bar, A decided to retire so B won the Event. I will report back to the Bar on your opinion!