Transfer: Southampton—London (incl. LHR/LGW) train, car, other?

[Magiemae41]

Hi All, 

 

I've been trying to read all the responses, but have just confused myself.  😊

 

We will be flying into Heathrow Airport a day before our cruise and need to get from the Airport to Southhampton (Hotel to be decided next) and then at the end of the Cruise, Norwegian Star 09/16/20 we will need to get from the Cruise Terminal to the airport for a 2:30 pm flight.  

 

Can anyone help me with the best way to do this please?  There will only be 2 of us. 

 

Thanks so much!

Mae

[happythoughts]

I’m sure someone will chime in with more knowledge . In the meantime, there are several private companies that you can hire and I am pretty sure there is also a bus. Not sure if a train is available from the airport. Are you interested in a private car service? Many have been recommended on this board and I can list them if interested 

[Magiemae41]

Thanks Happythoughts

 

I guess I'm interested in all options.  I see that NCL offers a transfer from the ship to the airport for $65/per person, but no options prior to the cruise.  

 

Wondering if there is a train from the airport and then we taxi to hotel, or if we must take a private car or bus from the airport?

 

Mae

[gnome12]

19 minutes ago, Magiemae41 said:

Thanks Happythoughts

 

I guess I'm interested in all options.  I see that NCL offers a transfer from the ship to the airport for $65/per person, but no options prior to the cruise.  

 

Wondering if there is a train from the airport and then we taxi to hotel, or if we must take a private car or bus from the airport?

 

Mae

There is no direct train from Heathrow to Southamption. However, the National Express bus has been regularly recommended.

https://www.nationalexpress.com/en

[scottbee]

On 1/22/2020 at 8:57 AM, Magiemae41 said:

We will be flying into Heathrow Airport a day before our cruise and need to get from the Airport to Southhampton (Hotel to be decided next) and then at the end of the Cruise, Norwegian Star 09/16/20 we will need to get from the Cruise Terminal to the airport for a 2:30 pm flight. 

 

A private transfer will be approx £80, a coach (National Express) varies but is typically £5-20/ea depending on how far out you book.  I'd just take the coach.

 

Rail sounds great, but goes in the wrong direction from Heathrow, toward London, so there is no direct rail service from Heathrow to Southampton.  (there is direct rail from London's Gatwick airport, just not Heathrow)

 

[Magiemae41]

Thanks ScottBee!  I'll look  into that.

[EuroDate20]

Does anyone know if it's easy to take the National Express from LHR to Southampton?  Our Virgin Atlantic flight gets in to Terminal 3 at 10:40 a.m.   DH has difficulty walking long distances, and we'll be each pulling our luggage.  If we take the coach, can we safely make a 1 p.m. departure?   What stop in Southampton is closest to the Southampton Harbour Hotel?  

 

Thanks to all!  

[John Bull]

6 hours ago, EuroDate20 said:

Does anyone know if it's easy to take the National Express from LHR to Southampton?  Our Virgin Atlantic flight gets in to Terminal 3 at 10:40 a.m.   DH has difficulty walking long distances, and we'll be each pulling our luggage.  If we take the coach, can we safely make a 1 p.m. departure?   What stop in Southampton is closest to the Southampton Harbour Hotel?  

 

Thanks to all!  

 

From T3 you have to get to Heathrow Central Bus Station - it's about ten minutes but much is on a travelator.

 

Aircraft to arrivals hall should be 90 minutes, mebbe a little longer. So if your aircraft is on-time (flying west-to-east with the jet-stream they usually are) you should be at the bus station by 12.30.

But no guarantees - you don't have a huge window for delays (though on a random date the timetable shows a 1.15 departure time from Heathrow central bus station).

 

You want the Nat Express coach to Southampton Coach Station.

Southampton Harbour Hotel is too far to walk from there with luggage & DH's dodgy undercarriage, so take a taxi from the rank at the coach station, £8 to £10

 

By far the most up-market hotel in the city. 

With coach x 2 + taxi your journey will work out at about £55.

A private transfer would cost about £40 more, but no worries about timing and less walking. Recommendations dotted around this thread. 

 

JB 

 

 

[EuroDate20]

Thanks JB!  I think it's best to do it the easy way with a private transfer.  We'll likely be tired from the long flight and less hassle is welcomed.  

[Globaliser]

8 hours ago, John Bull said:

So if your aircraft is on-time (flying west-to-east with the jet-stream they usually are) ...

 

Flying in any direction, they usually are on time. There is nothing special about aircraft flying eastbound across the Atlantic.

 

At airports like Heathrow, airlines can be penalised if their flights are routinely off-schedule, whether by being early or by being late - so schedules allow for winds (including seasonal variations).

 

The most important thing about planning is to allow and plan for the possibility that things will go wrong, as they will from time to time. Fortunately, National Express makes that easy.

[TYTY]

We have reserved a private car from Heathrow to the Premier Inn London County Hall.  How much would I tip the driver?

[John Bull]

1 hour ago, TYTY said:

We have reserved a private car from Heathrow to the Premier Inn London County Hall.  How much would I tip the driver?

 

Whatever you think they're worth.

Seriously - its not like in the States.

 

- Scruffy, inconsiderate driving, getting lost, or uncommunicative. Zilch !!!

- Professional & competent. £5?

- Smart car, friendly & helpful driver, smooth driving, a hand with the luggage, mebbe pointing out a few sights en-route. £10?

 

That'd be my parameters.

But not necessarily the same as other folk.

Back to "whatever you think they're worth".

 

JB 

 

[TYTY]

1 hour ago, John Bull said:

 

Whatever you think they're worth.

Seriously - its not like in the States.

 

- Scruffy, inconsiderate driving, getting lost, or uncommunicative. Zilch !!!

- Professional & competent. £5?

- Smart car, friendly & helpful driver, smooth driving, a hand with the luggage, mebbe pointing out a few sights en-route. £10?

 

That'd be my parameters.

But not necessarily the same as other folk.

Back to "whatever you think they're worth".

 

JB 

 

Thanks I knew you'd be able to help!

[de13]

Just finished reading through posts and some help is needed as I just booked cruise today:

 

I arrive in Southampton Via RCCL Anthem on Friday, April 24th and am traveling solo. I am trying to determine best way to plan my weekend. I am staying in London for wknd, (hotel TBD) and not sure how to get to London to do this, whether to rent a 1 way car, bus, or if a tour... Tour would be ideal and less hassle, but not private tour, as too expensive for me alone. I am OK with car and driving on opposite side road since did this in another country last summer. Would need figure out where to drop off car in London. Reason for tour or ca rental is Friday, I would like to arrive and visit Highclere Castle (tickets open for Friday only) and possibly Stonehenge on way to London hotel that eve. The castle is my priority. Previously toured Windsor and most tours go there or don't go in Highclere. 

 

Sat and Sunday- stay in London, trying to decide which area is best for hotel, considering I like to see Tower London, Buckingham Palace, Kensington, etc.  Sunday my flight is from LHR at 6, so will need to get there for flight.

 

Suggestions are truly appreciated!

Diana

 

[SarahD112]

We fly into LHR early Thursday, May 28th...board ship on 29th...off on June 6th, fly out early evening on the 7th. We would have liked longer in London, but it’s all we can do, time-wise. My thought is to take the train from Waterloo to Southampton. It’s the kids first trip to Europe (they’re 20 and 17) and we’d like to see as much as possible, so trying to figure out where to stay before cruise and after, to make the most of the day and a half on either end. So I guess it’s more important to stay near things to see/do, and taxi to Waterloo from wherever. I’ll post in another forum for the what to do part, since this is a transportation site - but looking for feedback on where to stay to make it easiest all around. As we only have a few days on either end, we want to stay in London before and after. 

[dickinson]

7 hours ago, SarahD112 said:

We fly into LHR early Thursday, May 28th...board ship on 29th...off on June 6th, fly out early evening on the 7th. We would have liked longer in London, but it’s all we can do, time-wise. My thought is to take the train from Waterloo to Southampton. It’s the kids first trip to Europe (they’re 20 and 17) and we’d like to see as much as possible, so trying to figure out where to stay before cruise and after, to make the most of the day and a half on either end. So I guess it’s more important to stay near things to see/do, and taxi to Waterloo from wherever. I’ll post in another forum for the what to do part, since this is a transportation site - but looking for feedback on where to stay to make it easiest all around. As we only have a few days on either end, we want to stay in London before and after. 

 

I would suggest starting a new thread on this same board because you are looking to find out hotels.  This thread is about transportation.  

[phabric]

8 hours ago, SarahD112 said:

We fly into LHR early Thursday, May 28th...board ship on 29th...off on June 6th, fly out early evening on the 7th. We would have liked longer in London, but it’s all we can do, time-wise. My thought is to take the train from Waterloo to Southampton. It’s the kids first trip to Europe (they’re 20 and 17) and we’d like to see as much as possible, so trying to figure out where to stay before cruise and after, to make the most of the day and a half on either end. So I guess it’s more important to stay near things to see/do, and taxi to Waterloo from wherever. I’ll post in another forum for the what to do part, since this is a transportation site - but looking for feedback on where to stay to make it easiest all around. As we only have a few days on either end, we want to stay in London before and after. 

I have taken www.justairports.com from/to LHR/London hotel, cost is per car.

 

Check out www.internationalfriends.co.uk.  They go on embankment/disembarkment days from LHR, LHR hotels and certain London Hotels, Southampton.  Their tours stops at Stonehenge or Salisbury, Stonehenge, Windsor or Bath, Windsor.

 

I have stayed 4x at Premier Inn Waterloo.  I have walked from Waterloo train station to this hotel.  This hotel has a bar, restaurant, walking distance to Big Ben, Westminster Abbey, Parliament, London Eye, Thamas river, HOHO, regular bus, tubes, restaurants/pubs, Waterloo train station.

 

 

[John Bull]

On 2/2/2020 at 11:06 PM, de13 said:

Just finished reading through posts and some help is needed as I just booked cruise today:

 

I arrive in Southampton Via RCCL Anthem on Friday, April 24th and am traveling solo. I am trying to determine best way to plan my weekend. I am staying in London for wknd, (hotel TBD) and not sure how to get to London to do this, whether to rent a 1 way car, bus, or if a tour... Tour would be ideal and less hassle, but not private tour, as too expensive for me alone. I am OK with car and driving on opposite side road since did this in another country last summer. Would need figure out where to drop off car in London. Reason for tour or ca rental is Friday, I would like to arrive and visit Highclere Castle (tickets open for Friday only) and possibly Stonehenge on way to London hotel that eve. The castle is my priority. Previously toured Windsor and most tours go there or don't go in Highclere. 

 

Sat and Sunday- stay in London, trying to decide which area is best for hotel, considering I like to see Tower London, Buckingham Palace, Kensington, etc.  Sunday my flight is from LHR at 6, so will need to get there for flight.

 

Suggestions are truly appreciated!

Diana

 

 

Hi Diana,

 

Can I suggest you DONT rent a car to drive into London. Driving, navigating and parking is awful.

 

Can I suggest that if you want to rent to visit Highclere or Stonehenge (doubt you ll have time for both, but they,re both pretty easy to drive) you rent from LHR and return the car to LHR, then travel into London by Heathrow Express (for hotel in Paddington) or Nat Express bus (for hotel in Victoria) or tube (for hotel close to a stop on the Piccadilly line) or pre-booked private transfer (35 to 50 GBP, depending on hotel location).

 

If you choose a hotel close to a tube station, all the places that you,d want to visit in the city are very easy to reach.

 

You could visit Stonehenge on the way from your central London hotel to your ship in Southampton, International Friends offer a cruise tour/transfer coach for your ship, with pick-up from hotel, 90 to 120 minute visit to Stonehenge en-route, and drop you at the ship.

Price includes Stonehenge admission (importantly its “anytime” admission, far easier than having to figure an arrival time to book if you drove there).

I,m travelling at the moment, poor WiFi and elderly I-Pad, so cant post a link to International Friends or their booking agency London Toolkit. Search this forum for links or ask google.

London toolkit is also very good for info, transport and other logistics in London and Southampton

 

JB 😀

[Alaska05]

Looking for best type of transportation from Heathrow to London Marriott County Hall.

 

We will be arriving around 6:45 a.m. on a Monday in June 2020.

 

Will traffic be horrendous?  Is it best to pre-arrange private pickup or take a taxi?  Just don’t want to get stuck in traffic and have the taxi meter running.  Are taxi fares a set price?

 

Thanks for any advice.

[John Bull]

11 hours ago, Alaska05 said:

Looking for best type of transportation from Heathrow to London Marriott County Hall.

 

We will be arriving around 6:45 a.m. on a Monday in June 2020.

 

Will traffic be horrendous?  Is it best to pre-arrange private pickup or take a taxi?  Just don’t want to get stuck in traffic and have the taxi meter running.  Are taxi fares a set price?

 

Thanks for any advice.

 

Heathrow to County Hall isn't the easiest of journeys by public transport, especially since you're likely to be travelling at commuter-time and with luggage.

 

A pre-booked private transfer is the way to do it. There are dozens of transfer services operating out of Heathrow,some good, some awful.

Try https://www.blackberrycars.com/ (frequently suggested on Cruise Critic) or https://www.simplyairports.co.uk/ (one of the biggest).

Rates for pre-booked transfers are fixed, getting caught in traffic will not affect the fare. But check whether airport access & London congestion charge are included in the fare and the operator's terms for waiting times (if your flight or airport formalities are delayed). Total cost should be around £45.

 

Simply taking a London taxi from the rank at the airport is about the most expensive way to travel, even when traffic is light. At a vague guess around £80, and subject to travel distance and time.

Hailing a cab can be quick and easy for short hops in central London, but way too expensive for longer journeys (yours is about 15 urban miles)

 

JB 

 

Edited February 20, 2020 by John Bull

[Alaska05]

6 hours ago, John Bull said:

 

Heathrow to County Hall isn't the easiest of journeys by public transport, especially since you're likely to be travelling at commuter-time and with luggage.

 

A pre-booked private transfer is the way to do it. There are dozens of transfer services operating out of Heathrow,some good, some awful.

Try https://www.blackberrycars.com/ (frequently suggested on Cruise Critic) or https://www.simplyairports.co.uk/ (one of the biggest).

Rates for pre-booked transfers are fixed, getting caught in traffic will not affect the fare. But check whether airport access & London congestion charge are included in the fare and the operator's terms for waiting times (if your flight or airport formalities are delayed). Total cost should be around £45.

 

Simply taking a London taxi from the rank at the airport is about the most expensive way to travel, even when traffic is light. At a vague guess around £80, and subject to travel distance and time.

Hailing a cab can be quick and easy for short hops in central London, but way too expensive for longer journeys (yours is about 15 urban miles)

 

JB 

 

Thank you so much for your advice.  This is exactly what I wanted to know.  I’ve been reading this thread and have learned a lot.  Thank you for all your contributions and sound advice.  Have a great day.

[cc cruiser]

Hello Good Friends!

 

We will be traveling in and out of Southampton in May.   We will arrive two days precruise and stay in London (Where??  My next research project) 

 

We will take public transportation from London to Southampton....or perhaps an excursion. (International Friends does not offer one on our embarkation day)

 

My question is about our return to London.  We have decided to rent a car in Southampton and drive to Heathrow for a flight the next day.    I have a list of places we are considering visiting on the trip to Heathrow, but I am having trouble determining what is feasible.   I was hoping a local could suggest an itinerary that would work.   I know we can’t visit all of these places but our interests would be Salisbury, Bath, Cotswold, Brampton and Windsor Castle (that is the only must on the list) 

 

What do you think would be the best route for some of these sites?   
 

Thanks for helping an old lady who couldn’t navigate Google Maps or Trip It!

[ikesyd]

Looking at options for our transfer from Southampton to Premier Inn Hotel Kings Cross on Thursday August 20th.

 

Option 1: Catch a taxi to Southampton Coach terminal then National Express to Victoria Coach terminal then taxi to hotel. If we do self disembarkation how long should we allow after docking to book the time of bus.

Option 2: Catch a taxi to Southampton Coach terminal then National Express to Victoria Coach terminal then train to St Pancras/Kings Cross - how difficult will this be with a suitcase each? Are there lifts or escalators at both stations?

Option 3: Private transfer from Southampton to Hotel - any preferred companies?

Option 4: Catch a taxi to Southampton train station then train to Waterloo then train to St Pancras/Kings Cross - how difficult will this be with a suitcase each? Are there lifts or escalators at all stations?

Any other suggestions? Many thanks.

[John Bull]

On 2/24/2020 at 1:02 AM, cc cruiser said:

Hello Good Friends!

 

We will be traveling in and out of Southampton in May.   We will arrive two days precruise and stay in London (Where??  My next research project) 

 

We will take public transportation from London to Southampton....or perhaps an excursion. (International Friends does not offer one on our embarkation day)

 

My question is about our return to London.  We have decided to rent a car in Southampton and drive to Heathrow for a flight the next day.    I have a list of places we are considering visiting on the trip to Heathrow, but I am having trouble determining what is feasible.   I was hoping a local could suggest an itinerary that would work.   I know we can’t visit all of these places but our interests would be Salisbury, Bath, Cotswold, Brampton and Windsor Castle (that is the only must on the list) 

 

What do you think would be the best route for some of these sites?   
 

Thanks for helping an old lady who couldn’t navigate Google Maps or Trip It!

 

Since Windsor is bucket-list and last admission to the castle is 4pm, that determines what you can achieve elsewhere. Latest you'll be thrown out of Windsor Castle is 5.15pm. If you arrived dead on 4 pm you'd have 75 minutes. That's just about enough time to make a decent fist of it, though 2 hours would be better.

 

On most ships you are likely to be able to disembark from 7 am (haul your own luggage from your cabin) or from 7.30 for assisted disembarkation (you may have to ask at guest relations to be assigned a 7.30 slot, citing your onward travel arrangements), and most car rental agencies near the cruise terminals are open from 8 am.

If you can quote your ship and disembarkation date I can mebbe be a bit more specific.

 

You can certainly fit in Salisbury (historic centre, magnificent cathedral, etc) and Stonehenge  before Windsor. 

Salisbury is about 45 minutes drive but unless you delay leaving the car rental agency until closer to 9am, on a weekday  you'll be mixing it with commuter traffic entering Salisbury.  (I can offer a quiet and scenic route to Salisbury across a corner of the New Forest, adding mebbe 15 minutes to that journey time, but you - or some kindly computer-literate 6-year-old relative  - need to be able to download googlemaps).

Salisbury is well worth 90 minutes or more.

Stonehenge is only about 20 minutes beyond Salisbury  (30 minutes via the Woodford Valley instead of the main highway).

You'd be very wise to pre-book a timed slot for admission to Stonehenge. I can help with that.

Stonehenge is worth about 90 minutes, & certainly no more than 2 hours.

Stonehenge to Windsor is about 75 minutes by main highway, make that 90 minutes including parking.  I don't think that there's a worthwhile more-scenic route from Stonehenge to Windsor.

So even if you dallied on the way you'd be in Windsor by 2.30 pm. 

This route, incl a corner of the New Forest and the Woodford Valley totals about 2 hrs 45 minutes driving.

https://goo.gl/maps/VpSY9fidoHnjkoFt7

 

Bath and Windsor (with or without a tick-the-box drive-by of Stonehenge) is also possible but a little more rushed.

Depart Southampton , say, 9am.

Direct route Southampton to Bath about 2 hours.

You pass thro Salisbury but I doubt you'll have time to stop, other than mebbe a photostop at the cathedral.

A deviation to drive-by Stonehenge will cost less than 10 minutes, but all you'll see of it is this  https://goo.gl/maps/mkVizf5K85sqvFpTA and there's a very firm "no stopping" there.

Arrive in Bath at, say, 11.30 pm.

Bath is worth at least 2 hours.

Depart Bath at, say, 1.30 pm.

Bath to Windsor by the main highway is about 2 hrs.

Arrive Windsor 3.30 pm.

Total drive-time about 3 hours 30 mins.

https://goo.gl/maps/2oE15t9PWkGqhgY58

 

The Cotswolds

.... are all about scenic country driving more than the places to visit.

When we've spent time there we haven't set out a route-plan, we've just meandered and enjoyed getting lost. - it's that sort of place 

A bee-line from Southampton to somewhere like Lechlade, then a hazy and lazy route through the Cotswolds, then a bee-line to Windsor would be about 4 to 5 hours driving, so plenty of time for teashops, pubs and the like.

But I doubt its worth, you could achieve more with places like Salisbury or Bath.

Hopefully Cruise Critic's Cotswold resident eagle can chime in.

 

Brampton

There's a Brampton in Cumbria, which would add the small matter of  about 600 miles to your journey.

Wanna try again? 

 

Or does International Friends offer a tour-transfer on your disembarkation day?

Choices include Salisbury+Stonehenge, or Bath, or the Cotswolds.

And all of them include Windsor

https://www.londontoolkit.com/travel/southampton_london_transfers.htm

SOUTHAMPTON TO LONDON CRUISE SHIP SHUTTLES & TOUR TRANSFERS 2020

Much more comprehensive and better value than their London-to-Southampton tour/transfer because they're not constrained by ship registration/embarkation time.

And certainly simpler and easier than DIY by rented car.

Downsides are that it's their itinerary & timing rather than your own, and time at Windsor castle is likely to be quite limited.

But a well;-respected tour/transfer operator.

 

JB 

 

Edited February 27, 2020 by John Bull

[John Bull]

6 hours ago, ikesyd said:

Looking at options for our transfer from Southampton to Premier Inn Hotel Kings Cross on Thursday August 20th.

 

Option 1: Catch a taxi to Southampton Coach terminal then National Express to Victoria Coach terminal then taxi to hotel. If we do self disembarkation how long should we allow after docking to book the time of bus.

Option 2: Catch a taxi to Southampton Coach terminal then National Express to Victoria Coach terminal then train to St Pancras/Kings Cross - how difficult will this be with a suitcase each? Are there lifts or escalators at both stations?

Option 3: Private transfer from Southampton to Hotel - any preferred companies?

Option 4: Catch a taxi to Southampton train station then train to Waterloo then train to St Pancras/Kings Cross - how difficult will this be with a suitcase each? Are there lifts or escalators at all stations?

Any other suggestions? Many thanks.

 

There are pros & cons choosing between Nat Express coach or the train. Coach is simpler and cheaper (just £5), train is quicker, but there's little in it.

Southampton's coach & train stations are close enough to each-other as to make no difference.

---------------------------------------

On Nat Express's current timetable your best options are from  Southampton coach station 07.30  am or 08.40 am.

For most ships the 07.30am is possible with unassisted disembarkation from about 7 am, but that leaves you no wiggle-time.

Way better to book the 08.40 am coach.

 

Decide for yourselves whether to disembark unassisted before 7.30, or standard disembarkation (for which you may have to ask at guest relations for an early disembarkation time-slot, citing your onward travel arrangements).

There might be a line for taxis, bear that in mind. 

Quote the name of your ship or cruise terminal, which might affect that decision.

 

Victoria train station is a simple and level 10 - 15 minute walk from Victoria coach station. 

There's a direct tube line from Victoria train station to Kings Cross/St Pancras.

It needs a Londoner / tube regular to advise how easy to negotiate those tube stations with luggage. 

From Victoria coach station to Premier Inn Kings Cross is 5 miles / 30+ minutes by taxi. At a guess at least £20, mebbe more.

........................................

Train fares to London Waterloo vary enormously, the current walk-up fare is over £46 but there are restricted advance fares (available from about 8 weeks out) as low as £15.40

On the current train timetable your best bet is the 08.30. Timing is ideal, and the advance fare £15.40. To see the advance fares you'll need to choose a random weekday date in March. The advance ticket prices rise closer to the date, and sometimes sell-out. They're only good for the train time that you choose, miss that train and the tickets are trash - you'll have to catch the next one at the walk-up fare. (same applies to Nat Express tickets, with the added disadvantage that the coaches are nowhere near as frequent and do book-out.)

Timetabling and ticketing are liable to change, so you need to diarise a date in July to book.

(there are also hourly trains from Southampton to London Victoria. But they take a circuitous route adding an hour to the journey time, and they present no advantages in your circumstances, so best avoided) 

 

There's a direct tube line from London Waterloo to Kings Cross/St Pancras.

Same comments as above from Victoria.

Ditto taxis.

................................................

A private transfer will cost vaguely around £130.

Try ...  

https://www.smithsairportcars.co.uk/

https://westquaycars.com/

http://www.aquacars.co.uk/

All are based at the Southampton end, so the driver won't be caught in motorway traffic heading to your pick-up.

..............................

Some ships offer coach transfers to London Victoria coach station - not worth the much higher fares.

But some offer a ship's coach transfer to Kings Cross / St Pancras. That's aimed at passengers bound for the Eurostar trains to mainland Europe, but would be ideal for you. Just be aware it might not be great value.

.................................................

Or, if you want a tour-transfer to London this pasted straight from a recent post of mine

Or does International Friends offer a tour-transfer on your disembarkation day?

Choices include Salisbury+Stonehenge, or Bath, or the Cotswolds.

And all of them include Windsor

https://www.londontoolkit.com/travel/southampton_london_transfers.htm

SOUTHAMPTON TO LONDON CRUISE SHIP SHUTTLES & TOUR TRANSFERS 2020

Much more comprehensive and better value than their London-to-Southampton tour/transfer because they're not constrained by ship registration/embarkation time.

And certainly simpler and easier than DIY by rented car.

Downsides are that it's their itinerary & timing rather than your own, and time at Windsor castle is likely to be quite limited.

But a well;-respected tour/transfer operator.

------------------------------------

Only other option I can think of is to walk. 

80 miles, about 26 hours.

Probably a bit far if you have luggage 

 

JB