Q. 1. During active duty, we frequently find ourselves in locations where there are no Catholic priests. The military Chaplain is Protestant and as such, only a Protestant service is offered. If I attend the Protestant service, will not fulfill my Sunday Obligation in the Catholic Church?
A. 1. No! The Catechism of the Catholic Church is very clear on this matter, to fulfill your Sunday Obligation, you must attend a Catholic Mass:
"The first precept [of the Church] ("You shall attend Mass on Sundays and holy days of obligation and rest from servile labor") requires the faithful to sanctify the day commemorating the Resurrection of the Lord as well as the principal liturgical feasts... by participating in the eucharistic celebration, in which the Christian community is gathered." [CCC # 2042]
When it is impossible to attend the Holy Mass, celebrated by a Catholic priest, you have no obligation to attend Mass. Under no circumstances should you attend a Protestant service and take bread at their service. Such would be a denial of the Real Presence of Jesus in the Holy Eucharist of the Catholic Church.
The Code of Canon Law # 1248 recommends that under such circumstances, Catholics should gather to take part in the Liturgy of the Word for an appropriate amount of time.:
"It is specially recommended that the faithful take part in the Liturgy of the Word if it is celebrated in the parish church or in another sacred place according to the prescriptions of the diocesan bishop, or engage in prayer for an appropriate amount of time personally or in a family or, as occasion offers, in groups of families."