Whew! - lucky there OFB, amazing how load you can yell when you need to.
My closest call was in an old 1960's plywood runaboat, a locally built Australian boat with an 80hp Johnson outboard. I set off with my brother-in-law and a friend from the boat ramp early, planning to make it to the my secret spot at mouth of the Port River before high tide, when the snapper are always biting. It was still dark, clear with no wind, and the moon gave plenty of light. We cruised down the undeveloped mangrove lined North Arm, the Johnson purring nicely and getting the boat up on plane easily. Life was good!
I handed over the helm to Terry, my brother-in-law and pulled out my newly acquired handheld GPS to check the distance to the secret fishing spot. Turning onto the main shipping channel, the lights of the industrial complexes reflected beautifully on the mirror-like water. I was facing aft showing my buddy the GPS, and noticed we were cruising at about 20 knots. I was just thinking - This is a bit fast considering it is still dark; Maybe I should tell Terry to slow d....... WHAM!
We stopped dead in the water, and the 3 of us were hurled into the bulkhead with a wave of water flooding the cockpit. I picked myself up, trying to work out what happened. Surprisingly the boat was in one piece and we were not sinking. Everyone was still alive, although bruised and battered. I looked to see what we hit but there was no other boat in sight, no channel markers nearby, nothing floating in the water. What the #### did we hit? Terry had the air knocked out of him and was having trouble talking. "Big wave; A wall of water" he finally croaks. But how? We were still miles from the river mouth; No other boat to cause a wake. It doen't make sense.
After surveying the damage (cuts and bruises, fuel tank ripped out of hold down, compass destroyed by flying bodies, tackle box contents spread everywhere, but no apparent hull damage) we cleaned up, we continued on our way. It was getting light now and we had missed the turn of tide.
We looked at the big new complex on the riverside where they were building the Navy's new submarines. Then I realized what must have happened. I heard that they were beginning sea trials on these 250+ foot monster Collins class submarines. At the time they were the largest non-nuclear submarines in the world. They obviously throw out a big wake when they dive.
I still wonder if they saw us coming and had to take evasive action. Luckily I don't think they were armed yet.