Even if you live nowhere near the coast, two marine frequencies to have in your scanner are the ones below. The range of HM Coastguard is pretty good:
156.00000 - NFM - Channel 00 - HM Coastguard
156.80000 - NFM - Channel 16 - Distress
156.00000 - NFM - Channel 00 - HM Coastguard
156.80000 - NFM - Channel 16 - Distress