They were returning home, after fishing all night, and needed to pass near an area off the beach that has low water depth, in order to enter the harbour of Nazaré (see here http://marinas.com/view/marina/11576
, thanks sailor"!!!).
Most man were sleeping, when a freak wave hit them and threw some of the nets and stuff to sea, which was jammed into propeller.
The boat then became uncontrolled and rolled into beach. Now we know waves at the beach were 15' high, in surf area.
Accident happened at 7am, still dark.
By the way, these were professionals of the sea, not people like us that go to sea for fun, they have to go to feed their families. They go when you and I stay home watching movies. They do fishing school for years. Poor guys didn't even have time to get to their safety gear. Well That is life.
The last acident with fishing people dead, in portugal was 2 years ago.
Accidents with non professionals is very very rare over here.