Programming with sporadic sports (surfing)

I am having a hard time getting my upper body workouts in because I am sore for days after the thoracic bridge series and from surfing. If I'm sore from previous days surfing should I still do my upper body workouts anyway? I am afraid of overtraining. Surfing involves 3 hours of propelling myself by arms only with the resistance of a heavy neoprene wetsuit. 

Today would be the programmed day to do my upper body PEs but I plan to surf tomorrow and possibly two more days after. I don't want to go into the weekend already sore. Should I buck up and do it anyway?  I can't plan my "surfing days" since the swell comes and goes. Or should I just wait until later next week and hit it then?

If it's writing you off and you can't enjoy the things you like you are hitting it harder than you can currently handle. This is one of those moments to remind yourself that training is intended to make you better at athletic pursuits  or the reminder that works for me, that Coach's boys did conditioning BEFORE skill training. That should give you a rough barometer;  of course you should be getting after your training, but you need to be able to function afterwards too

If your athletic pursuits of choice are not necessarily regular, there is nothing wrong with having some adaptability built into your training too. Say you have have 2 upper body GST  assignments to complete in a week, with at least 24 hours between them (more might be better but we're going for completed before we look at ideal). Some weeks you might be able to square them away on Mon and Thurs. Sometimes they might be any other combination. That is absolutely fine (provided it does not become an excuse to procrastinate or miss workouts of course!)

Something is wrong if you can't enjoy what I imagine is one of the reasons you picked up GST in the first place. It should be making you better at those things, not conflicting, so that balance needs to be corrected.

Overtraining here is not a real risk (note that DOMS is very distinct from overtraining which is prolonged and systemic ) so to somewhat flippantly and directly answer your question, suck it up some and if the sets are coming in take advantage of that while the getting is good. The gym will still be there.

Of course it would be the Australian coach that responds to the surfing question!     OK , i definitely need help with programming.  On my schedule with "Coach Summer's Recommended", he only has me doing one of each Foundation a week, which I always thought was light. I just added the 3 stretch series.  So lets say I surf 1-2 days a week.  If I have DOMS from surfing I just go ahead and knock out the workouts, right? Maybe if I am extra exhausted just do the stretch series and wait 24 hours before another upper body?

Killer advice from Jon! The only thing I'd like to add is that the intensity of your TB session sounds a bit too high. You can probably help your soreness and overall recovery a bunch by simply keeping the intensity at a 3-4 out of 10 for your stretch sessions. This will likely reduce soreness a bit and make your training and surfing more manageable. I do this to keep myself climbing and training regularly. Very similar situation as climbing is also upper back and shoulder intensive. 

As for frequency of your upper, lower, and core workouts, I suggest keeping them at once per week for quite a while. With surfing 1-2x per week, you'll appreciate the recovery for now.