Who, me Bob? Bruce, since he has a 12V TM, actually it's very simple...unless he wants the "house" to be isolated from the TM batt as well. If he's really not running anything on the boat while operating the TM (except maybe a fresh charge from the livewell pump occasionally), then just have him hook up the TM batt to batt 2, with the TM positive lead coming off the common post. Just switch over to batt 2 when using the TM.
If, however, he plans on running the livewell pump full time, and maybe the stereo, then I would recommend a Blue Seas ACR tied into his start batt, as his house loads will eat in to the reserve to operate the TM. Not having an ACR would mean nothing to his start batt, but his ability to run the TM at full thrust would be diminished...