switch for boat lights

i'm trying to install a switch for my boat lights it;s a 2 way switch when i hook the two leads one to hot the other one to ground when i turn the switch off it blow's the fuess why is it doing that ? i need helpJames J P

Your two pole switch has two settings: Open and closed.  With one lead to +12v and the other to Ground, when you close the switch you're shorting 12v to ground, thus popping the fuse.  To connect your lights, you have to run +12v from the power source to one input, and the +12v side of your lights to the other input.

no i need them to come on at the same timeJames J P

You need to ground both of the lights.  Then connect the positive lead of both lights to one terminal of the switch.  Connect the other terminal of the switch to a power source.  If you want the lights to be able to come on without the key, you need to get power from a constant source.  If they are to only come on with the key, connect it to a wire that is only hot with the key on.