The self-association of sodium carboxylates 1a-5a in aqueous solution has been studied by H-1 NMR and dye solubilization. Amphiphile 1a, the derivative of 1,6-methano[10]annulene bearing a carboxylate on the bridge carbon, is an example of a "contrafacial amphiphile", a rigid molecule with distinct polar and nonpolar faces. Amphiphiles 2a and 3a, the sodium salts of 2-naphthylacetic and 1-naphthylacetic acids, respectively, are isomers of la with more conventional amphiphilic architectures. Amphiphiles 4a and 5a are derivatives of 1a with extended nonpolar surfaces. Concentration-dependent H-1 NMR data indicate that self-association of 1a-5a is weak and occurs in a stepwise fashion. Up to its aqueous solubility limit of 0.54 M, contrafacial amphiphile la does not solubilize the hydrophobic dye orange OT, but conventional isomers 2a and 3a solubilize the dye above 0.33 and 0.50 M, respectively. Contrafacial amphiphile 4a also does not solubilize orange OT, but 5a does solubilize the dye. The properties of isomers 1a-3a were compared also at the air-water interface. via tensiometry. Between zero and 0.15 M, naphthyl derivatives 2a and 3a cause a significant lowering of surface tension, but contrafacial amphiphile la has little effect on surface tension up to 0.35 M. Crystal structures of carboxylic acids 1b, 4b, and 5b show that the aromatic face of the 1,6-methano[10]annulene unit that is anti to the bridge engages in "herringbone" interactions with neighboring aromatic surfaces, which is similar to the behavior of conventional hydrocarbon aromatic moieties. The solid state packing patterns observed for 1b-3b allow a speculative rationalization of the differences in surface activity among 1a-3a.