Marine Hull insurance covers nearly everything that floats and moves, starting with rowing boat to huge ocean-going tankers. Besides that, hull underwriters will not hesitate to insure non-propelled objects, which may occasionally move such as floating docks, buoys, transshipment barges and even floating hotels. Furthermore, we can say that vessels under conversion or construction are also dealt with by marine hull underwriters.
HULL & MACHINERY (H&M)
This is very basic of the marine hull. Skeleton, if we may say so. This policy will cover your vessel, including hull, machinery, gear and equipment against loss or damage. Normally you would be also entitled to claim for your ship's proportion of salvage, salvage charges, general average as well as wages and maintenance under your H&M policy, but you need to check your wording first.
DISBURSEMENTS, FREIGHT, INCREASED VALUE (IV)
Underwriters would normally say that there is a big deal of difference between these insurances, but all in all, these are basically the same as you would be entitled to claim certain amount of money (which you have agreed beforehand with you underwriter friend) in excess of insured value of your vessel in case she will be a total loss, whatever actual or constructive.
LOSS OF HIRE (LOH)
It goes without saying that you need some money to run your ship and you would expect some profit from her operation as well. Ok, but you would naturally be left without income once your ship is not working, so that's why here is LOH insurance. This policy will compensate daily amount stated in your policy (again you have to agree on it before) whilst your ship is under repairs following an accident covered under H&M insurance. Underwriters would normally allow 14 days deductible before they open their wallets, but this still is nothing in case of reasonably serious damage.
MORTGAGEES' INTEREST INSURANCE (MII)
This policy would normally be demanded by bankers (or, as we say, mortgagees). It protects the mortgagees' interest in the insured vessel in case H&M underwriters would refuse to settle a claim due to breach of warranty stated in H&M policy, e.g. H&M is allowing vessel to sail only within Baltic sea, but your vessel ends up in collision in English channel - you hardly can expect you H&M underwriter to pay for it, but MII policy will protect mortgagees' interest anyway.
BUILDERS' AND CONVERSION RISKS
This is insurance for the vessel under construction. The cover is normally against all risks of loss or damage to a vessel under construction or conversion and during trials and would include certain liability risks as well. This insurance is normally taken by ship builders.