Don't be deceived by a wide opening to a large body of water -currents can still be strong, especially on a full moon. Everyone should be aware of this potential hazard. In our case, the whale watchers could have been summoned back toward shore before the current took hold. Keeping the group together is imperative for practical and psychological reasons. The stronger paddlers can help with towing or rescue situations in the event of capsize.
Groups are also a more visible search target when held together.
When attaching a towline, be aware this can heighten anxiety. It helps to reassuringly explain that the person being towed will still be able to control the direction and stability of their own kayak. It helps if every member of the group has a sense of responsibility for keeping an eye on each other. In strong seas it is dangerously easy for paddlers to simply focus on their own paddling and drift apart. Don't exhaust your resources all at once.