to act when you make contact with TF,you need to quickly determine the position, and if it is possible to intercept, you do not lose anything if you have the power to confront any of the ships and if it is shallow or deep water does not matter but some deep water has advantage,strike quickly and then disappear, but see a TF as a standard convoy although they move faster than a "normal" convoy but remember you have the upper hand as long as you are Sharpe and is under the surface