ponds where you will find this combination splashing and diving and swimming and floating - or, if they're unevolved types - crawling hesitantly, hiding under protective shells.
The Crab and the Scorpion (or Eagle) have an almost uncanny instinctive understanding of one another. They share, not all, but nearly all vices and virtues. The faults and foibles of one are either possessed by or intensely admired by the other. It's called empathy, and Cancer and Scorpio can always count on this as a supportive influence in their relationship, whether adult and child, business associates, lovers, married mates, friends, siblings, or other relatives.
A child, or children, will typically, in some way, play an important role in their lives, as the relationship grows and endures (and probably it will), either a troublesome or sorrowful or a happy and magical role, almost from the time they first meet. Sometimes, sadly, this takes the form of children one or both deeply desire, but cannot possess, for one reason or another. More often, however, children and young people are a blessing to these two. If not literally children, then the childhood of the Crab or the Scorpion (or both) will be, in some strange way, the basis for initial attraction and sympathy. They will enjoy comforting one another concerning a sad past - or laughing and dreaming together over a happy past. Yesterday is always very near to Moon souls, and Scorpio also looks back, secretly, with nostalgia.
Both the Crabs and the Eagles tend to never forget a kindness. Likewise, they mutually share long memories for hurt or injury. Wound either Cancer or Scorpio, and the memory will linger, never fading, occasionally for a lifetime. But there the similarity ends, for the Crab will seldom try to even the score, preferring to cry and nurse injured feelings alone, cauterizing the wounds with liberal doses of self-pity, while the Scorpion will bloody well see to it, in one way or another, that there is returned an 'eye for an eye, a tooth for a tooth' - a bruise for a bruise, a dented fender for a dented fender, an insult for an insult, and so on. This is a reaction (though not a very positive one) to the Scale-balancing act Scorpio has already learned from the sign behind - Libra. Making things come out even. But while Libra sorts it out evenly through logical mental processes, Scorpio balances matters in, shall we say, a more tangible and instant way.
The Crab's hurt seldom, if ever, causes an urge to attack. The reflex action of the wounded Cancerian is to retreat, often remaining mistrustful of that person or situation forever… whereas the word 'retreat' is nearly unknown to an Eagle. Scorps may appear to give up, to retreat or disappear. But they'll return. Inwardly, these people would almost literally prefer to die than to lose a conflict or come out on the short end of someone else's stick. This goes for love affairs, business deals - soccer and marbles (depending on the age and sex). Yet, the Scorpion doesn't always consciously obtain the satisfaction of revenge. That is, he or she need not necessarily (though some do it deliberately) take an overt action against the offender. The intensity of a Pluto-powered thought alone will do it.
Nevertheless, there is an unearthly sweetness in the Scorpio aura, superimposed upon the determination not to be smashed without teaching the smasher a lesson, and it is this sweetness, this gentleness and sensitivity, which allows the Crab to trust the Eagle.
Since both are of the Water Element, when Cancerians and Scorpions who have heavy afflictions to their individual Suns at birth get together, they can drown in drink, drugs, or other forms of escape, including sexual promiscuity - dragging one another down deeper into the depths, until they've reached the ocean floor. The swim back up is not easy. For these, the extraordinary magnetism of the 5-9 attraction is a trap. Some associations of this type have even become mutual victims of dark arts like hypnotic control, psychic attack, voodoo, and black magic. Scenes like séances with a trance medium are best avoided by either - and especially by both together.