According to various search and rescue authorities and figures compiled by the ARC and other offshore rallies, more cruising boats have been abandoned in the last 30 years because of rudder failure than for any other reason. A recent example is that of the yacht Dove II, which lost its rudder 400 miles east of Barbados while on passage to the Caribbean in December 2016. The crew, a couple with their children and another crewmember, were unable to improvise an emergency steering system and had to be rescued, abandoning the boat.
Rudders are an essential design feature that should dictate the choice of boat. Suspended rudders have gradually migrated from racing to cruising boats and, unprotected by at least a partial skeg, are extremely vulnerable. If you cannot avoid a boat with this kind of rudder, at least insist that the lower half of the rudder is sacrificial, as this is where it is most likely to be hit by debris. Regardless of the type of rudder, there must be an adequate emergency backup steering system that is easy to set up and known to all members of the crew.