I was stuck at Haverford for two days in bad weather once, waiting for a window to cross the Irish sea. I tried asking the ferry companies and the captains. They refused because of insurance reasons.
Eventually I had to go with the weather as is. I went low level all the way along the ferry route. I buzzed two of them in the rain on the way over.:)

Ive done the crossing loads of times in r44's Squirells and once in a R22, I picked up a 25 knot headwind as I coasted out of Cahore point for H-West I'd ran out of positive thoughts by the time I'd got there !!!!!

Seriously though its very straight forward if you need to speak to anyone then you will have to be at least 3000 ft, but its an easy flight and a great adventure if its your first time, take a life jacket, PLB etc and you won't have a problem, just make certain you don't mix up cloud for land !

Forget the passenger. Small one man dinghy strapped into left seat. Immersion suit and lifejacket. PLB. Lots of fuel. GOOD weather!! Working GPS. Flight Plan. Then cross wherever you like! Dublin-Caernarvon is good because you have an active SAR station on the route at RAF Valley :)

I've deliberately avoided this post, but curiosity has got the better of me - so here's my 2 bobs worth...

There have been lots of suggestions and opinions offered ranging from the downright sensible to the pretty wierd.

The immersion suit with lots of warm stuff underneath is a must, as is the good quality lifejacket (not the self-inflating type) with spray hood. A reliable SARBE/PLB is also a must-have. A dinghy? Well of course.... No mention of floats so far, so I guess that you won't have them.

If you do have to ditch and assuming that you pull off a perfect touch down in a benign sea-state, you have get yourself and your "little life raft to keep the CAA happy etc." out of your helicopter which will have the bouyancy of a punctured crowbar. Have you done a dunking course? If you haven't and it comes to the worst, you will be doing it for the first time for real. Not an ideal arrangement.

Now, we all know that engines can't tell that they're over water, and as you say "But ya know some times engines don't stop!" Engine failure is only one reason why you might end up in the water.

If you have to do this trip, plan for the worst - don't hope for the best. Take the shortest overwater route and only in the best weather.

I did this trip once in a 206 without floats. It was summer, we had the suits, jackets, dinghy, SARBE, flares, you name it. Precisely one mile short of half-way, the engine chip light came on. Conversation dried up rather as we headed for Valley (it wasn't the shortest over water route). We made it, but although the chip was the size of an ants eyelash it could have had a fully legible part number on it for all we knew.

Forget about landing on the ferry, they'll NEVER let you do that.

Good luck, let us know when you've done it.

TRC Good reply
 

TRC has it right but don't forget the ELT (Emergency Transmitter). I have made many cross water trips of +100Nm. I took 4 man life raft, ELT, crash kit (3ltrs water, survival gear, fishing line + hooks etc) all placed on passenger seat attached to life raft. Didn't wear a survival suite, just a life jacket, but I was in the Med in Summer. Would wear one over Irish sea.

The ELT will help SAR find you.

Good luck