SCUBA-2 signal-to-noise maps at 850 μm for the Fabulous, Jackpot, MAMMOTH-1, and Slug ELANe (yellow star). Sources detected at over 4σ are marked by cyan circles, and the size of the circles represents 2× the FWHM of the beam. The white curve bounds the effective area of every map, which is about 10′ (∼5 Mpc) in diameter. The quasars that contribute significantly to the powering of the corresponding ELAN are marked as yellow stars (coordinates in Table 1).