Boat motor won't start after wrong battery connection

I have a 1988 omc cobra 2.3L, the other day I was going to start it up, while getting everything ready I had my friend connect the battery. He connected the positive to the negative and vise versa for a few seconds before I noticed. After reconnecting the battery correctly it will not start,when I turn they key there is no sound like it is not getting power to the starter. The radio and fish finder will not turn on but the trim works.Th only fuses I can find where under the steering wheel console there is about 8 fuses I checked them all and they seem fine, but I went ahead and changed 5 of them that is all I had.but it still won't start and the electronics still don't work. What can this be and is there any other fuses that are located in a different place? Please help any advice would be greatly appreciated. Thank you very much

Lasha, I don't know if you have received a workable reply to your posted question, but I hope this is helpful: My 1990 5.8 L Cobra had the same issue several years ago. On top of the engine, near the rear of the compartment are two rubber capsules containing two 50-amp fuses. These may have been burned through then the mis-connection was done to your battery terminals. The capsules pull apart and you can replace these fuses, which are available either from your OMC dealer, or from most hardware or home improvement stores. They are inexpensive and should be a simple solution to your issue, if I am right. Let me know if this solves your problem.

Thank you very much I found the fuse and it was Burnt out. I replaced the fuse and it started right up. Thank you very much everyone for your help.

What would you suggest if both of those 50AMP fuses check out OK (I actually replaced them proactively) however, I still cannot start the boat...NO POWER whatsoever (I have a separate thread on this issue)...

-Jeff