LED's are the current pinicle of MArine lighting aside from the sun.
Bulbs will last about 10-15 years(50,000 hours), and then only lose about %25 of thier power.
So basically your gonna replace only a few times in your life.
they produce much less heat.And your electric bill will be a small fraction. Say from $75 a month for a few 250 MH's to $10 a month for the equivalent LED system. LED's are win from all angles. You can even put them on a dimmer, or create your own lighting schemes that range from greens, reds, oranges, yellows, blues, and whites.
Im going to be doing a DIY led system in the next month or so, for my 125 DT. There are a few members hear that have already done so, so you can read up on them.
Or you can buy them pre-made from the big companies and pay thousands of dollars. For my 125DT it would run close to 4 grand! OUCH! Or I can DIY for around $700-900