Down rigger location
I run 4 riggers on my 18 ft. Mirror Craft. As u can see in the pic there's plenty of room to land the fish on the starboard side. I'll swing the corner riggers out or up if it's empty and move the rod to a different holder. Swivels are very helpful in the corners. I run long arms out the back as well and haven't had any issues with the motors. Hope this helps.
I have been running 4 riggers off small boats for years with no problems.
Two short arms off the back corners, two long arms off the side gunnels.
The side gunnel riggers need to be close to the transom of the boat but still enough room to use the rear corner riggers easily.
You need to have enough pole holders that when a fish is hooked up and someone is fighting the fish, someone else can move the stern poles to positions away from the stern of the boat. Thus opening up space to net the fish. Return poles to previous positon when the fish is netted. This is easier than it sounds.
If a starboard side rigger goes off and the rear starboard corner rigger pole is right in front of you, I just move the pole to the far port side. I don't release it and I don't raise the rigger. The whole rear starboard corner and end of the boat is clear to net your fish. Now the person on the pole and the person at the wheel must do their part and it should lead to a successful netting of the fish.
Good fishing! Shellfish
More of a question on mounting instead of location I was going to mount a 12in rail off the side/back of my 2014 Starcraft 176sc I was wondering since I can't get to the underside of I should install well nuts, toggle bolts, or ??? To help insure the screws don't pull Also was thinking of going with the cannon tracks and swivel 4in raised down rigger base. Anybody use this setup? Down rigger is a cannon uni troll