Here's something to consider as well....
" it doesn’t take long for fast swimmers to overtake and swarm the back end of prior waves. This means there’s a moment, for a poor swimmer, when the entire complexion of the swim changes. There’s a new group in which this swimmer is now enmeshed, and that group is moving past and through this much slower swimmer and, perhaps, overtop that slower swimmer."
Taken from a Slowtwitch article
Limiting Deaths in Triathlon
Written by: Dan Empfield
Date: Mon Aug 13 2012
" it doesn’t take long for fast swimmers to overtake and swarm the back end of prior waves. This means there’s a moment, for a poor swimmer, when the entire complexion of the swim changes. There’s a new group in which this swimmer is now enmeshed, and that group is moving past and through this much slower swimmer and, perhaps, overtop that slower swimmer."
Taken from a Slowtwitch article
Limiting Deaths in Triathlon
Written by: Dan Empfield
Date: Mon Aug 13 2012