For a starting character, hidden tattoos should be enough. Usually, max for a standard wizard would be +2 offensive power +2 offensive control so one hidden tattoo in each hand. If you are submerged and take 2 refinements, one to raise element specialization to +2 control, +1 power, and one to raise foci to +3 offensive power, +3 offensive control, you can have your thaumaturgy free specialization be a focus specialization, allowing your foci to have a bonus 1 higher than normal for the same size.
And that would make your submerged wizard into human artillery; 9 power, 10 control for offense, 6 power, 7 control for defense.