Danger Pictogram?

[vive equinox]

Yyesterday, for the first,  i had a danger pictogram in my 800.  In the high To the left on the screen.

the Id was something To 25-27 ,the sound was huge.  I think this is a big target.  I didnt dig that thing.  I was in the beach on beach1. It was anything like that:  ⚠️ 

Anybody know what is mean? 

[Dukester]

Beach overload indicator....

[vive equinox]

Ah okay . Thank i didnt have seen that in manual.  

Yes in this part the sand is very black.