The Edges of the Water is the worst danger for a skipper.

The worst nightmare for a skipper is to ground his Boat, not to talk of the Navigator. It happened to Vestas Wind sailing in the VolvoOceanRace after properly validating the Mauritius Mark. 

Vestas wind grounded 

Sailing just ahead of Alvimedica, they sailed East of the Cargados Carajos Shoals , where the first 3 boats, Abu Dhabi, Brunel and Dongfeng due to their advance and the changing windconditions sailed West of these Shoals. Vestas Wind was sailing east close along Ile de Sud, too close apparently as they grounded with a 19Nm Boatspeed. The Boat turned 180 degree and got stuck with the stern. The dagger-boards and rudders were all broken in the accident. 
Alvimedica, suspended temporary the racing to assist Vestas Wind when required. After the crew were in safety, Alvimedica resumed the Leg 2 race to AbuDhabi; a recalculation of the time lost in the rescue assistance will be made by the R.C. 

Luckily none of the crew were injured. Later in the Night the crew could wade through knee deep water unto a dry part of the reef and later picked of by a RIB of the rescue services and brought to the Isle de Sud, which has limited accomodation. 
Today, I read that all crew has arrived safely at Mauritius, with the fishing vessel "The Eliza", (reason I published the accident in my blog). They have secured their boat, removed pollutants as oil and fuel and taken valuable parts of the Boat with them. 
The Crew is said to travel to AbuDhabi, where a detailed briefing will be done. 

Further trials will be made to salvage the Boat and if possible to repair it. This might however not be fast enough to allow Vestas Wind to start on Leg 3 of this VolvoOceanRace.