Mako- Question
Would like to hear more about the situation that was pooping your aft deck because our aft hatches are not water tight and the bilge space below freely runs into the lowest bilge of the boat in the engine room.
So would like to know the sea state and wind conditions that were causing that; and what was your speed?
I was 3 days in solid high-20 foot seas with occasional really big boys coming up behind us. Running at 8.25 knots in a 65 footer steelie. We shallow-tacked downwind and were constantly fighting the wheel to keep us on a straight course. Bumped up the throttle to keep water flow over the rudders. I hope to never be in conditions like that again, but I know I will. The AP could not handle it and by coincidence went down (easy fix once we tied up in Bodega Bay).
Your description of your boat sounds like the majority of boats out there, sail or power, few of which have watertight bulkheads. Water will run from the chain lockers all the way back to the rudder post. This may work fine for a weekender, but if you're planning on taking your boat far then consider trying to tighten up your bulkheads as much as possible and then install more bilge pumps of course, for each compartment. Ideally you will have 4 WT areas (chain locker collision, staterooms, engine room, steering room lazarette).
BTW, regarding to all the comments about autopilots, I would say they are spot-on with what I've experienced as well. I remember my older boat which was cable steered and had a Wood Freeman. Wonderful old school AP with an electric starter motor as its drive. However its ability to steer was certainly subpar compared to today's electronic APs. In heavy following seas I had to hand steer, usually in 2 hour shifts. A big challenge for any AP is that it can't see following seas coming up behind you. However, it was commented above that new AI technology lets the computer learn and anticipate seas. Not sure how effective that is because each breaking wave is different, but it's a step in the right direction. Can't imagine what the cost is for a unit like that though.
Just reread your first post. The focus of your thread is regarding heavy weather, so we'll avoid the obvious "just avoid it" response
Am only familiar with GB42's by reputation but it sound like you want to improve its offshore abilities and safety. I would think about reducing down-flooding in extreme conditions (engine intake vent location, pipe them down to below the sole plate if necessary), those rotten sliding windows, replace your windows if rather thin, look at your doors for watertightness, WT bulkheads, gasket or replace that aft hatch, hatches need to be secured down and not rely only on gravity, etc.
Regarding windows, the 1600GT captain who taught me told a story of delivering a GB42 off the West Coast, heading uphill (north) unfortunately into horrible seas. Big sea punched out the forward window, which of course turns the situation into a hellish condition. The 2 with him (boat's owner and then a friend) both bailed on him when they finally reached port, and then he finished the delivery solo. So when I started going offshore I would carry precut plywood sheets, fasteners and power tools. However nowadays I would prefer to replace the windows. Double the thickness of the glazing with laminated tempered glass. Even if the glass shatters, the lamination will hold it together. The chances of blowing out a well-bedded window like that are minimal especially if you are conscientious about avoid heavy weather.
Then think about adding roll stabilizers. Roll is not fun for anyone even if you never get seasick. Plus it's dangerous because it quickly leads to fatigue, which is certainly not what you want when fighting through storm conditions for days on end. There are plenty of threads here on TF about stabilizers and perhaps your solution might be simple rolling chocks (bilge keels) which are not very expensive to install and should knock off 1/4 to 1/3 of your roll. That, combined with tacking to avoid beam seas, will improve your quality of life offshore.
Wow this turned out to be a long response, ha.
