I went into the jellyshroom caves with the prawn suit before I got the grapple arm or jet jump upgrades and...
Lets just say that I lost an hour of my life
The exact same thing happened to me, luckily I already knew how to make the grapple arm and managed to get it out (at te cost of some damage caused to it by a curious Crabsnake)
I didn't have benzene at the time so...
Hey look,someone braver than me
What do you think?