Things every diver should know but MANY don't.

1- If your team is not ready to leave yet, RUN AWAY from the landing zone once the 2-minute extraction countdown is over (NOT BEFORE THE COUNTDOWN), Pelican one will hover above and provide POWERFUL covering fire around the landing zone until the end the game. (apparently it would eventually run out of ammo if enough shots were fired)

Edit: +1 Pelican one COULD BE damaged or destroyed, once it's damaged (ON FIRE) it WILL FLY AWAY when the FIRST diver gets on, SO DON'T GET IN THE PELICAN IF IT'S ON FIRE! if your team still needs the samples, make sure the ONE designated diver collects all samples and then he would be the ONLY ONE gets on the pelican.

++ a damaged pelican would only take 1-2 hits for it to be destroyed, but it won't blow up, divers just couldn't get on it anymore, then the team needs to wipe themselves to force the mission for a finish.

+2 You can drop samples/gears by pressing "X" on the keyboard. (or holding down on the d-pad on PS5)

2- No team needs to DROP WITH MORE THAN 2 of the same backpack or support weapon. divers can equip their teammate's backpack and support weapon then the team would have 4 more slots for eagle/orbital/sentry.

3- DROP YOUR SUPPORT WEAPON AND GUARD DOGS FOR YOUR TEAMMATES ONCE THE COOLDOWN IS UP! DROP YOUR SUPPORT WEAPON AND GUARD DOGS FOR YOUR TEAMMATES ONCE THE COOLDOWN IS UP! DROP YOUR SUPPORT WEAPON AND GUARD DOGS FOR YOUR TEAMMATES ONCE THE COOLDOWN IS UP!

4- Mortars are always BAD for bugs unless it's the missile launch mission AND guard dogs are always BAD for bots.

Edit: I should clarify that points 2 3 4 are the things you should know IF you would like to increase the overall efficiency of the team on HELLDIVE difficulty. I am not gonna argue with anyone about those, if you know you know, if you don't then you will understand them eventually with more games played.

5- You can adjust the radar by yourself, there is a sound cue once you hit the right spot. if you are not sure, dial it back, then listen for it again.

Those are just on the top of my head, you are welcome to add them.