36 has a support leg 47 and positioning leg 49 the outer faces of the support legs 46 47 have a plurality of narrow ridges 52 53 extending along their length in order to promote good frictional engagement of the support members 46 47 with the top and bottom walls 24 26 of the skimmer passageway 20 in the embodiment shown in fig1 7 each rib 38 has a central outwardly curving section 60 when viewed from inside the pool and upper and lower inwardly curved sections 62 64 this particular configuration has been found optimal for deflecting floating objects away from the skimmer mouth ribs having other types of contours could be used provided that they readily deflect each individual rib 38 has a t shaped cross section as shown in fig4 to provide a combination of strength and flexibility which enables the skimmer guard 10 to be mounted and removed by snap fitting thereby rendering unnecessary the use of tools or fasteners for mounting or removal as is shown in fig5 7 the upper and lower support legs 46 48 have a pair of apertures 67 formed therein for receiving the lugs 70 of spacers 68 which are mounted thereon by a snap fit one or two spacers 68 can be used to increase the effective distance between the upper and lower surfaces of the guard 10 in order to seat snugly within a larger skimmer mouth 12 spacers 68 of varying thicknesses can be used this feature of the invention enables a single skimmer guard to be effectively used in skimmer mouths having openings of various sizes the lugs 70 are configured to snap in.