MSC has just released a new River Safety Handbook and DVD intended to be used by instructors and teachers. This provides more detail than the MSC Bushcraft manual and is a great resource for Trampers and Hunters.
As a MSC Instructor I can't recommend enough that trampers and hunters of all levels periodically attend a MSC River Safety course. The techniques for river crossing are evolving all the time with many small incremental changes that often get overlooked.
Re: Pack Straps - recommended technique - waist belt done up if it can be undone quickly(leave undone for non-quick release buckles), this limits the pack from rising up as the water get deeper and the pack wants to start floating. Undo the chest strap, two main reasons:
1)you may need to get your pack off in a hurry if you become entangled in a strainer or other obstacles and having more than one buckle to undo is a major.
2)since the pack will still rise up even with the waist belt done up and the strap may get high enough to place pressure on your throat.
The MSC course often provides the opportunity to find out what its like to exit your pack if it becomes ensnared. For those that have experienced this, it obvious that having more than one buckle to undo whilst underwater, possibly upside down and with a strong current flowing around you is a major issue to overcome.
