In the best of times, travel plans do not always work out and, with the outbreak of war in the Middle East, there is reason to be cautious about committing oneself in advance to expensive travel arrangements, such as a cruise.

Before reserving a cruise, passengers should become familiar with the line's cancellation policy and consider buying trip cancellation insurance to avoid paying a penalty if plans change.Insurance is available to cover a variety of contingencies, including terrorism that leads to a change in itinerary.

Cruise lines allow cancellation without penalty up to a certain date, then charge penalties in increasing amounts as the time for sailing draws nearer.

Passengers reserving a Royal Caribbean Cruises trip must notify the company in writing at least 45 days in advance of sailing to receive a full refund. A schedule of penalties applies after 45 days.

Between 44 and 30 days before sailing, the penalty is $100 a person for seven- and eight-night cruises and $200 a person for 10-night cruises. Between 29 and 4 days, the penalties double. No refund is given within four days of sailing.

Other lines go a step further, offering a waiver provision.

Holland America allows a passenger who pays $49 to $248 extra, depending on the length of the cruise, to cancel for any reason up to 24 hours before departure.

The waiver plan also offers up to $500 for baggage loss or damage. About 35 percent of all passengers take the waiver plan, according to J. Richard Skinner, a spokesman for the company.

One cruise line, seeking to allay Americans' fears about travel in Europe, is offering each passenger $1 million in accident insurance.

The day before the outbreak of war, Renaissance Cruises announced its AssurancePlus program, which covers accidental death or dismemberment of passengers on European cruises.

In the last week or so, some relaxation of cancellation penalties has been seen.

In addition to announcing its accident insurance plan, Renaissance said that it had eased its cancellation policy, allowing cancellation without penalty until 60 days before departure instead of the previous 120 days, and Lloyd Axelrod, a spokesman for Royal Caribbean, said that if someone were called to active duty, penalties would be waived.

"There may be other extenuating circumstances," he added.

"We will decide on a case-by-case basis."

Holland America's spokesman said that ordinarily passengers are required to buy the line's penalty waiver at the time of reserving a cruise, but the company is now allowing them to do so later.

Cruise lines that completely change their itineraries customarily offer a full refund to passengers not wishing to take the revised cruise.

The assumption in the case of people seeking refunds from a cruise line is that they have paid the fare published in the company's brochure.

But what if the passenger has gotten a discounted fare from a travel agency? In that case, the cancellation policy of the travel agent may supersede the cruise line's policy.

Marshall S. Feingold of Westbrook, Conn., found this out when he had to cancel a cruise to Bermuda and Nassau last year.

Notifying the cruise line 37 days prior to sailing, he expected to suffer the cruise line's published penalty of $100, but his travel agent held him to a stricter penalty - $300.

The agent argued that Feingold, who had received a 40 percent discount, was notified of the agency's cancellation policy when he received his confirmation.

Feingold complained to the cruise line, which replied that the agency was free to set whatever penalties it wished.

In addition, the agent pointed out that he had sent the passenger an application for trip cancellation insurance.

That application was for the Traveler's Travel Insurance Pak, which for $22 would have given up to $400 in cancellation coverage and $4,000 in emergency medical evacuation assistance.

Feingold could also have paid an additional $10 for up to 10 days of travel accident insurance and for $20 more purchased $500 worth of insurance to cover lost or damaged baggage. The total cost would have been $52.

For trip cancellation alone, the usual premium is $5.50 for each $100 of coverage; if the passenger wants to cover the entire cost of a $2,000 cruise, for example, to be protected no matter how late he or she cancels, the trip cancellation feature of the policy would cost $110.

The three elements - trip cancellation insurance, accident insurance and baggage insurance - form the basis of what is called a comprehensive travel policy.

The Travelers and other companies offer the three elements together or separately, but some companies offer only a comprehensive policy, at least in New York State, which, according to a spokesman for the American Express Travel Protection Plan, "is overly strict."

American Express's comprehensive policy, starting at $87 for a family plan of up to eight days' coverage, pays up to $1,500 for trip cancellation, trip interruption or delay, up to $100,000 for medical evacuation, up to $10,000 for injury or sickness and up to $1,500 for lost or damaged baggage.

The plan covers a husband and wife and children traveling together or grandparents and grandchildren traveling together.

One plan specifically designed for cruise passengers is SafeSail, offered by Access America.

Under this comprehensive policy, an individual pays $47 for trip cancellation and trip interruption coverage of up to $400 and also receives a medical transportation benefit of up to $10,000, travel accident coverage of up to $25,000, baggage protection of up to $500 and some other benefits like missed connection of up to $1,000.

One of the advantages of buying trip cancellation insurance is that it is possible to obtain reimbursement up to the moment of departure (not just 72 or 24 hours beforehand), or even if the trip needs to be cut short.

Another difference between trip insurance and a penalty waiver is that many trip policies cover such eventualities as the hijacking of an airliner or cruise ship and cancellation or interruption of a trip because of a terrorist incident in a city that the traveler had intended to visit.

In the case of a terrorist attack, however, the incident usually must have occurred after the policy was purchased and within 30 days of the policyholder's planned arrival date.

Other benefits offered by some trip insurance policies: reimbursement, in full or in part, for money paid to a cruise line, airline, tour operator that goes bankrupt or otherwise defaults on a program either before the trip begins or while it is in progress.

Such provisions, however, generally do not cover travel agencies since they are usually bonded for such defaults; travelers should check to be sure that their travel agent has such bonding.

Under some policies, cancellation penalties are reimbursed regardless of the reason the passenger cancels (a no-questions-asked provision), but under other policies (SafeSail, for example) there must be a medical reason - the death of a family member or the sickness of a traveling companion or injury to the policyholder, for example.

And policies that specify ill health or an accident usually exclude pre-existing conditions.

With the help of a conscientious travel agent, however, the restriction on pre-existing conditions might be overcome.