The talk test is a simple way to measure relative intensity. In general, if you're doing moderate-intensity activity you can talk, but not sing, during the activity. If you're doing vigorous-intensity activity, you will not be able to say more than a few words without pausing for a breath.
I would not suggest it. Anything can happen on a boat.
Offer workplace training about cleaning up spills
It depends on the women’s level of activity
