In crossing salt-marshes, your sole concern should be to get over them quickly, without any delay.
Salt marshes are large, flat, hazardous expanses that are found in river deltas. More generally, they represent difficult open terrain where the army is exposed and where it is difficult to fight or even rest when marching.
As such, it is best to estimate the size of the marshland and seek to get across within a day. Alternatives includes boats by sea or moving further upriver.
In business there are many ways to be exposed and open to attack. Wherever you are, constantly review possible threats.