Watermans Lotion SPF 18 3.4oz Sunscreen. For those shorter sessions or overcast days when you don't need much. A lighter version of our Sun Cream, the SPF 18 offers the same cosmetic grade, non-slip, zero migration, long lasting protection you expect from Watermans: Applied Science. Our functional focus ensures that it will not run in your eyes or negatively affect your performance. 3.4oz. Watermans Applied Science.