Why do they insist you dock stern in? I think you should dock whatever way is the easiest and safest. In my boat (and my understanding is most sailboats are similar) I have very little control moving slowly in reverse so I park her bow-in.
I'm still trying to understand the insistence some people have with backing into the slip ... I've seen several people in my marina this year try again and again and again to back in, failing and getting damn close to running into something when it seems to me they could just go bow-first and save a lot of trouble.
1980 S2 9.2A (30') in Anacortes, WA
Aux power 13hp Volvo MD7A