I genuinely didn't understand this movie, but it was so fascinatingly bad that I carried on watching. 'Adventure Girl' reminds me of an Ed Wood movie, because it attains his easy breezy cheesy sleazy level of ineptitude. This movie also reminds me of 'Perils of Nyoka', 'Sheena, Queen of the Jungle' and the old Victorian music-hall recitation 'The Green Eye of the Yellow God'.
As far as I can tell (and I could be wrong) 'Adventure Girl', starring Joan Lowell, is based on a book she wrote called 'The Cradle of the Deep'. Now here's where the confusion starts. IMDb lists that book as a novel, as in *fiction*. Ms Lowell's self-righteous narration in this movie seems to indicate that 'Cradle' is non-fiction, and that this movie is her rebuttal to all the people who disbelieved the veracity of her book. I suspect that the truth is somewhere in the middle: it's my guess that 'Cradle of the Deep' was published as fact, but was actually a cradle of lies and was freely denounced as such.
There's nothing believable in this ultra-low-budget movie, which purports to be a documentary re-enactment of true events. Joan Lowell plays herself, or a fictionalised version of herself: a distaff version of Johnny Weissmuller's Jungle Jim. Allegedly, she went to Guatemala to steal (I mean discover) a fabled emerald that's been propping up the eye socket of a Mayan idol. I'm absolutely positive that someone connected with this movie has read the English poem 'The Green Eye of the Yellow God'.
Off to Guatemala sails Joan, with her handy crewmen Bill and Otto. Their sailboat gets caught in a gale and loses its mast. Bill gets blown overboard, and hardy Joan dives in after hm while the sailboat is caught in the gale and speeds away without them. Joan and Bill are forced to tread water in the Gulf of Mexico for two hours. Meanwhile, the camera is right there with them, steadfastly recording this.
Eventually the merry crew end up in the Guatemalan jungle, where the natives immediately capture them and make plans to roast Joan at the stake. This sequence is gobsmackingly bad, with the 'natives' staring into the camera and giggling in embarrassment whilst they mumble unga-bunga curses in the general direction of Joan. We are constantly aware of the camera (and the cameraman) grinding away while Joan is allegedly in dire need of assistance.
Eventually, Joan gets into a bitch-slap fight with a Guatemalan jungle woman, who looks suspiciously Caucasian. All of this is offered in absolute earnest, yet all of it is howlingly faked and often hilariously so. Throughout the film, Joan's turgid narration insists that we recognise the ongoing fiasco as an accurate re-enactment of genuine events.
This film rates perhaps one point out of 10, but I laughed so hard and so often that I'm willing to throw in two extra points. On the other hand, I don't want to encourage this sort of mendacious ineptitude. Split the difference and rate this rubbish 2 points out of 10.