Maybe I didn´t understand you correctly, but to my knowledge the number displayed in your skillbook ins´t your skilllevel, but the amount of spells/abilities you have allready learned.

With Hydrosophist 1, you are able to learn Armor of Frost, Hail Strike, Rain and Restoration. Have you learned those spells and don´t those spells show up ?

Is there a number displayed under the hydro-tab in your spellbook ?