Steelfan, the broker you may have heard about is either International Marine Insurance Services, located in Maryland, USA - they often get good web coverage because they offer a proprietary policy designed for short-handed crews who sail internationally - or it was Pantanius if you are looking for European coverage.
Unlike the post above, out on the cruising trail I have met almost NO boats in Europe that aren´t insured. In the Caribbean, my impression is that at least a majority of boats were insured. Insurance obviously is something that needs to fit your financial circumstances. If the boat represents the bulk of your assets, one could fairly ask why wouldn´t you want it insured when cruising in foreign waters? If the reason is that, once you experience a loss the carrier might not pay, then you haven´t obtained enough info (examples of how the same carrier covered other losses, e.g.) to comfortably choose the company with whom you want to insure.
Some boats carry liability insurance only (which won´t protect you from the loss of your boat but will cover you from damage caused to others by your boat - fuel spill, dock damage, collision with another vessel) while others carry a 'full' policy (hull coverage + liability). For more threads on this topic, consider visiting the Discussion board at the SSCA site (www.ssca.org
Because sweeping generalizations like ´save the money and buy a bigger anchor´ can be less than helpful, here´s a real world story to ponder: experienced crew in well-found yacht, entering an atoll in the Tuamotus, and they clipped the reef (cloud over the sun suddenly; large eddy current in the channel; unexpected wind gust; momentary loss of concentration; there can be a hundred reasons why this would happen). Partial rudder and skeg loss, limited steering, weakened quadrant, they are in the boonies, no infrastructure to fall back on, and they email their broker via SSB asking for advice. Answer: "Your choice: we can total the boat right now and you fly out, leaving the boat behind for us to worry about...OR you can try to sail her to Raiatea (nearest yard that could haul the boat; about 450 NM away) for repairs. Do what you feel is safest." End result: other cruisers pitched in, managed a suitable jury rig, and one buddy boat shadowed this boat on the run to Raiatea after helping injured boat´s crew get a good wx f´cast, where the boat was hauled and repaired, the policy covering all the costs except the deductible. (FYI: Broker was IMIS; carrier was Markel; boat was American with husband/wife crew). Interesting side note: carrier was willing, at broker´s suggestion, to offer $10K to any other cruising boat if they would escort injured yacht to Raiatea, just to reduce the probability the boat would be totaled.
Not all boat losses are total & due to hurricanes nor all policies unfairly written nor all carriers unethical nor all brokers unhelpful.