What's the earliest?

[Lured Inn]

What's the earliest you have put your boat into the slip?

[Play Dough]

Last weekend of April for me.  I was never slipped near my residence so never wanted to risk freezing of the motor or cabin fresh water systems.  I can't imagine having to trace a leak somewhere between the cabin and bilge in a split water line.  A couple extra weeks of boating isn't worth the risk to me...and I've seen plenty of snow on boats around the middle of April in the past.

[N II Deep]

last year I put in the first weekend of April,  the next day the wind shifted and blew Ice back into the marina area.  Lucky that no damage to boat, this year will be toward the end of April.

[Fishjay]

Middle of March to first of April if ice is not an issue 

salt water IO saves me from freezing motor 

I have three valves I drop open to release water around antifreeze jacket on motor great for early and late season