This is from the Standard Course Book of HSK5, segment 25. How to literally translate this:
This is my try:
正当(just when)水手们(the sailors)慌张(flustered)得(?)不知(not knowing)如何(how)是好(is good)时(time)，老船长(the old captain)命令(ordered or commanded)水手们(the sailors)立刻(immediately)打开(open)货舱(cargo hold)，使劲儿(erhua of make an effort)朝(?)里面(inside)放水(turning on the water)。
As you can see only the second clause makes sense to me... I am far away from understanding the rest.
My specific questions:
1: 正当[...]时 means when? 正当 is pronounced zheng4 dang4 or or zheng4 dang1?
2: 慌张得: What exactly is its meaning? Remind me please the general use of 得 in this kind of cases.
3: 如何是好: Is it one word? What does it mean?
4: 使劲儿: What is its meaning?
5: 朝: Is it pronounced zhao1 or chao2? What does it mean?
6: 放水: It is something about water, but what exactly?