Looking at the manual for your boat that Dave linked to, there are a few key points you can check for voltage. Dave's and ChrisJ's suggestion to check the house "breaker" is a good one. If that's tripped, that's your problem. If it isn't, then it is time to start tracing voltage from the batteries to the house breakers and fuses.
Page 26 has the PDP (power distribution) schematic. There should be a 100 amp fuse between the batteries and the house switch. That fuse should be close to the batteries. If the fuse isn't blown and you have voltage there, the next stop is the house switch. Check for voltage at the switch if you can. After the switch, the schematic shows a 175 amp breaker, which would be the house breaker that Dave and ChrisJ identified and is shown on page 18. Odds are good the problem will be somewhere between the batteries and that last house breaker since it sounds like all DC accessories, regardless of what fuse block or breakers they are on, are not working.
Good luck!
Gini