1. whether possession taken on behalf of second respondent2. agreement that first and second respondents take possession of motorboat and quote for work3. first respondent took possession on behalf of second respondent pursuant to agreement4. Was second respondent liable as joint bailee5. whether primary judge erred in admitting opinion as to value of motorboat6. opinion not shown to be based on specialised knowledge in turn based on training or experience7. assumptions on which opinion based not stated8. no explanation for reasons for conclusion as to value9. evidence should have been rejected