Judging depths
A character can accurately judge the depth of water if he/she makes a dice roll using his/her PE + Swimming (including Judging water safety/Judging depths specialisms). The difficulty value is equal to two times the depth of the water in metres. If the character fails the dice roll but is close (i.e. within 5 points), he/she will have a rough idea of the depth.
For example, Roger is an expert swimmer with a Swimming score of 5 and a PE of +0. He does not specialise in judging depths. His basic value is 5+ 0= 5, which gives him a certain result of 5. He is trying to judge the depth of the water at the bottom of a cliff. He decides to risk two dice and so rolls 2D-1. He gets a 5 and a 3, giving a dice roll result of 7. In fact, the water is 3 metres deep, which is difficulty 6 to judge, so Roger can tell that the water is that depth pretty accurately.
Judging current strengths
A character can accurately judge how strong the currents in an area are if he/she makes a dice roll using his/her PE + Swimming (including Judging water safety/Judging current strengths specialisms). The difficulty value is the current strength (used for Resisting currents). If the character fails, he/she will know that the current looks stronger than the dice roll result he/she achieved but not how much stronger
For example, Roger is an expert swimmer with a Swimming score of 5 and a PE of +0. He does not specialise in judging current strengths. His basic value is 5+ 0= 5, which gives him a certain result of 5. He is trying to judge how rough the sea looks. He decides to risk two dice and so rolls 2D-1. He gets a 2 and a 3, giving a dice roll result of 4. In fact, the sea is quite rough (difficulty 8) - all Roger can tell is that the water is definitely at least difficulty 4.