What makes a Good Tender?

An Introduction to Tenders

Here up in Yorkshire, all the locals know the phrase about the irritations that big things having smaller things attached have to put up with. Never is this phrase truer than when you are trying to source the right tender to go with your larger main boat.

Your requirement for a small boat could be as a tender for a small yacht, a larger cruising yacht, a tender for a fly-bridge motor cruiser, a run-ashore for blue–water cruising yacht or even a mini-me for your very own superyacht.

However the seven basic principles for picking a good tender are much the same, no matter what the size of your main vessel.

Here at Pennine Marine’s large building “somewhere in Northern England” we often get asked by a boat owner for our hands-on and practical advice about how to pick the best tender for a larger boat.

Since we now have in our office this new-fangled internet thingy, we can now share all our knowledge about boat tenders with the rest of you. We understand that the internet even reaches potential customers in far-away and sunny southern England, so we can export this knowledge to down to the Deep South!

We hope that this short piece of advice helps you to understand all ins and outs of buy a tender, in particular helping you to understand the hidden pitfalls of buying a small tender for your main boat (or as we call these pitfalls around here - “throwing your money down the disused mineshaft”).

You might as well read this advice on buying a tender. After all, who wants to select the wrong tender for their main boat? If you did pick the wrong tender, you will become the main talking point in the club bar, and not for any of the right reasons!

Key Requirements for Tenders

We all know that soft southerners writing for boating magazines in the Southampton Municipal Boat ting Lake Area (aka the Solent) manage to write pages of waffle about tenders. However, we here at Pennine Marine in Yorkshire don’t do waffle – so we don’t write for these boating magazines.

Getting the right tender for your boat all comes down to just seven key issues;

Capacity - how many people will be on board your tender?

Payload - what other large items will you be carrying?

Range - how far will a tender be travelling?

Lifting - how will you lift the tender on board?

Stowage - this is the vital one. Where will you keep it on board and what space is there for it?

Other Activities - will your tender be used for other watersports activities?

Other Requirements – colour matching, style matching, durability etc
 
Let us now explain these seven key principles of how to pick the right tender for you.
 
The Capacity of Your Tender

This issue of a tender’s capacity is frequently overestimated. Even experienced boaters often get this badly wrong and buy something to large and expensive. However the passenger capacity is the first key issue to consider when picking a tender.

The capacity of your tender will significantly affect everything else. Your tender’s size, weight, required engine power and stowage space will be determined by its capacity. Last, but not least, a tenders capacity seriously affects the cost of your new tender. Get the capacity of your tender wrong and as the locals say here - “nowt else will go right!”.

That is why we put capacity at the top of our list, as the issue to think of first when selecting a new tender.

Ask yourself the one simple question- “how many people will really be on board the tender at any one time?”

Most people simply do not need a tender which has a capacity of a full main boat load of passengers on every occasion. Most tenders often run ashore with only one, two or three on board.

If you occasionally need to take a full boatload, ask yourself whether you will be moored or anchored somewhere close to your destination. If you are, then a full boatload of passengers can often be ferried in two short hops to shore (or just do one hop and leave the most boring guest behind….).

The other question to consider with the passenger payload is the question that is not always obvious – are the passengers experienced? We consider this issue in more detail below.

PAYLOAD ON YOUR TENDER

In addition to passenger capacity, the amount of freight carried in a tender can easily double the total load on board a small boat. Items such as food, clothing, watersports kit, your lady wife’s handbag and especially diving and fishing gear etc are all bulky and heavy.

First of all, be realistic about whether you will actually be carrying all this gear on board your tender. It might be easiest to move your main boat alongside a jetty or quayside for a few hours, simply to load it all up, rather than buying a big tender to use just once or twice.

If you tender will definitely be carrying lots of gear, please think carefully about the choice of the tender’s floor. To carry lots of gear, the tender’s floor needs to be flat, strong and well-drained, so as to keep all your gear both dry and stable.

The boat’s balance and stability is vitally important when it is used as a payload carrying tender. A wider boat is also preferred, so the tender remains both stable and safe. This stability is vitally important when you (or your crew load) transfer gear both from the shore and then onto the main boat. This stability issue is especially important if you have to stand up in the boat to transfer a load. Remember that a small boat’s stability gets even worse in choppy sea conditions.

However having said all this about stability, many modern inflatable tenders and ribs (of all shapes and sizes) do have wider diameter tubes than their predecessors from ten years ago. This helps immensely with the overall stability of the average small tender.

Range

Many tenders are only ever used for short hops, especially in sheltered anchorages or harbours. For short range harbour work, any size of tender will often do the trick.

The range can make a big difference to the means of propulsion. A short range out to your big boat gives you the choice of either rowing, or starting up the outboard engine. Driving your tender a long way inevitable means an engine is essential.

However please consider the range you might need if you are going to be taking your tender to unfamiliar or unusual waters. Many areas worldwide, for example the Caribbean and the South-East coast of the UK, are notorious for having wide and very shallow sandbanks.

Having large areas of shallow water in your cruising area, often coupled with a large tidal range, will mean that the main boat has to stand or moor a long way offshore (and further from the bar in the evening). Using a tender in these circumstances can often mean that it is essential that you select a small tender but one with a higher speeds and a long range.

Longer ranges will mean you definitely will only want to do a single trip ashore in your tender, preferably with a full payload of passengers and gear all loaded and carried in one go. To keep the transit time down, larger outboard engines and a good turn of speed are often preferred in these circumstances.

Coupled with an assessment of the boat’s intended range, also consider the size of the tender needed for good sea-keeping. This is particularly important if the tender is to be used at night.

Any small tender is fun in harbour. However being on small boat a long way out from the shore can be more challenging than you first think, even for experienced boaters. These longer ranged excursions can become a concern, especially when operating a small tender at night and in a generally unlit area. This experience gets even worse when the weather turns against you and when there are nervous passengers on board.

Therefore seriously think about the range and whether this factor means you might need to consider a more seaworthy tender.

Lifting Your Tender on Board

Few boats now routinely tow a tender for anything other than the shortest hops. Firstly towing seriously degrades the main boat’s performance and fuel consumption. Secondly the consequences of the tow line breaking can be rather expensive (and very embarrassing to explain afterwards in subsequent bar room conversations).

Therefore nearly all tenders will be lifted up and stowed on board the main boat.

There are three main lifting techniques to consider- manual, davits, and roller ramps. It often surprises us here how common the key issues are between all three different methods (and we know that rich mill owners face the same challenges as poor working men)!

For all mechanised lifting methods, firstly and most vital is to consider the lifting capacity of any crane, davits or other fixed lifting gear that will be used to lift the tender. This lifting capacity will be marked by the manufacturer of the lifting gear as the SWL- Safe Working Load. This SWL must be the total all up weight of everything combined being lifted – the boat, engine and all gear. Most boat-builders still haven’t really got the hang of specifying lifting gear and boat builders do not build a lot of spare weight margin into their davits. Therefore this SWL limit needs to be considered with great care.

The second thing to consider with all mechanised methods is the headroom available to lift your pride and joy. This headroom issue affects not just the size of the tender, but also the size and length of the lifting slings being used. Again it is staggering how many Solent based boat-builders fail to properly consider the lifting headroom. The available headroom under the davits, hook or headroom inside a garage will often dictate the size of the small tender you can buy and safely lift on board.

For all manual methods of lifting and stowing your tender, please carefully consider how the small boat will be lifted on board your main boat. Yachts and motor cruisers with a stern swimming platform have a major advantage in these circumstances. With stern platform, the tender only has to be lifted a short way up and there is the added benefit that you are standing on a solid platform when lifting it. Owners of other types of big boats may not be so lucky. If you do need to manually (or femalely) lift your tender over the gunwales or side wires, then our experience says that you will quickly regret not buying the smallest, lightest and most featherweight tender available on the market.

This manual lifting problem can be made far worse if you are cruising or sailing short-handed at the time. This issue of being short-handed could be unexpected, for example caused by crew illness. You may need to consider manually launching a tender, whilst being single-handed and in adverse or challenging circumstances.

The other factor for you to consider for manually launching your tender is lifting the outboard engine. Outboard engines are not light and their awkward shape can make them tricky to lift up and down onto the tender, especially from some angles. You may need to restrict your tender down to a certain overall size, simply so that the outboard engine remains a sensible size and weight so you can easily lift the engine on board.
 
STOWAGE OF YOUR TENDER ON BOARD

Once your tender is aboard, the key question is “is where to keep it?”

Naval architect’s all prioritise hull shape and interior functional space at the expense of practical stowage. Therefore tenders tend to end up stowed in the “left over space”. We find that even superyacht garages are surprisingly tight for space. On smaller vessels, the tender stowage problem is often compounded by poor locker design and awkward access arrangements.

The two key choices for keeping a tender are normally “stowed complete”, or “stowed rolled”.

With any size or shape of tender, stowing the boat complete makes it far easier to deploy and use quickly once the main boat is moored up. However if the tender is stored complete and ready to use, then it needs to be fully secured against rough weather and the engine will need protecting. Please also consider that the space around it must be kept clear for the crew to be able to safely walk and work around the stowed tender.

Stowing the tender rolled or folded can be a real bind when it comes to use it, particularly if the tender is being frequently used. If it does need to be frequently used and cannot be left out, go for something small and fast to inflate - otherwise you won’t be getting the tender out very often!

For small tenders with small outboards, the storage of the engine somewhere reasonably dry can be problematical. Storing spare fuel can be a real problem, especially when cruising long-term on ocean going yachts.

You need to consider where the most practical place is to keep a tender on board, and also carefully consider the engine stowage. These requirements and dimensions are very specific to each individual main vessel.

Other Activities with Your Tender

In the paragraphs above, we have talked about the practicalities of keeping a tender- all a bit dry and boring. However once you have mastered the practicalities of where and how to use your tender, please think about what else you and your family could use it for.

With the smallest dinghies and inflatable boats, you are probably confined to short hops with family and friends.

For smaller yacht tenders, if you marry up an inflatable boat with a slightly bigger outboard engine than you might strictly need for use just as a tender, then some watersports fun beckons. A 3.6m inflatable with a 15hp can be a lot of fast fun.

Going slightly bigger again brings you into the small rib category. Whilst these smaller ribs would definitely need davits or crane launching, small ribs are well known for their “fast fun” potential and general long range exploring ability. With a rib on board, your main boat could even be left at home for a day.

Moving to the top of the scale are high performance jet boats. Jetboats are expensive, however they are the ideal combination of a tender’s three key characteristics, jetboats being a combination of being lightweight, with low headroom and high power.

Other Requirements for Your Tender

Selecting your tender obviously means you need to carefully consider the interface with the main boat. The other requirements you may need to think about when selecting your tender are usually;

Looking at the Details Appearance – will it match the main boat?

Fuelling - will you need a different fuel supply from the main vessel?

Weather Protection – be that hot, cold or wet. Do you need screens, bimini’s or even cuddies?

Navigation – will you need electronics to navigate long ranges, especially at night?

Radios – like navigation, will a radio be needed for safety?

We hope the section above helps you to resolve all the fundament design issues with your new tender.
 
OTHER ISSUES TO CONSIDER WITH A TENDER

We touched on some of these points above. Before buying a new tender, you need to look at a few other practicalities.

Who will be the passengers on board your tender?

We touched on this issue above. The key question to ask is “who will be the passengers on your tender and will they like being on the water?” If they do not, then you need to consider whether  the tender you are thinking about buying will feel solid and safe for these inexperienced passengers.

If you are going to travel regularly with boating novices, or those who always feel unsafe in small boats (these people are known as landlubbers), we suggest that you seriously think about buying a tender that is more stable than you might otherwise need. A tender with a rigid or semi-rigid floor and with a “grippy floor” gives a lot more confidence to nervous people. Psychologically a flat and solid floor may be very important for your inexperienced passengers, especially if you are going to be asking them to stand up in the tender when boarding the main boat.

Three different tender hull types – a rigid, inflatable or rib hull?

There are only really two main choices when it comes to the hull for a tender – inflatable hull or rib hull? Traditional rigid hulls are still used, however the practicalities of the on-board stowage issues often rule them out.

As we discussed above, the pros and cons of you selecting either of these two primary hull types come down to the lifting and stowage issues.

If you can lift and stow the rib, then this type of hull will be more robust. A rib will also give you a better seaworthy performance out on the water. However many rib hulls are heavy and bulky and this often counts against them being used as tenders.

For smaller tenders, inflatables win hands down if the overall weight and/or the available stowage space are your key practical concerns.

The hull and deck fittings

Boats have all kinds of attachments on the hulls. On a tender- either the smallest inflatable or a superyacht tender- it is surprising how problematical these hull and tube fittings can be. Deck and tube fittings used of a tender need to be practical, well positioned and robust.

Before selecting your tender, decide how you are going to use and stow the boat. Once this is decided, then you need to look carefully at your proposed purchase to see if it really will work properly for you in practice. Elements to consider on hull fittings are;

Tow rings
If you will tow your tender, are the tow rings substantial and well positioned for tow ropes?

Rowlocks and Oars
Are they correctly positioned for rowing and also strong enough for vigorous rowing?

Handles, Lifelines and Ropes
All tenders ultimately need controlling by hand for the final manoeuvre. Are lines and ropes substantial and well located? If they are, can you grab the tender, and if necessary lift it, with the lines that are fitted to it?

Valves and Pumps
Are these valves, pumps and gauges etc quick and easy to use – both to inflate and deflate?

(And can her indoors inflate the boat on her own? If she can’t, you will be doing it for her!)

For a larger tender, electric pumps may be needed to speed up the inflation. If so, is there an electric point nearby you can use?

Davit Lifting Points
Are these accessible and easy to use?  Are they positioned so that they work well with your davits and lifting gear?

The Floor
We touched on this issue earlier. Slippery floors in small tenders are at best a nuisance, at worst a serious safety hazard. Tenders, especially the small ones, are close to the water and always seem to attract spray. Water and smooth boat floors don’t mix well. This can be quite a concern, especially if you or your passengers are not quite as youthful as you once were. Will the floor drain easily or will your passengers need willies and all your gear be getting wet?

The Durability of Tube Materials
Tenders can get a hard life on board a boat – during long voyages they will often be left lying about “doing nowt all day” (so think of your tender as being a bit like the average teenager on summer holiday……..).

The downside of getting all these rays is that you need to think about the durability of your tender. If your tender is covered, or stowed below, then durability of the tubes materials will not be too much of a problem. If however the boat is regularly exposed to bright sunlight, then you might want to consider buying one made from the more durable materials.

In the UK, for most leisure users, using a normal standard PVC for the tender is fine. However the premium hyperlon/neoprene tubes will give your boat a longer life and therefore a higher residual resale value.

At latitudes well to the south of Skipton, for example in the Mediterranean, more serious consideration needs to be given to buying hyperlon/neoprene tubes. However even PVC boats in the Med which are stored out of direct sunlight, under cover, or only used for a few weeks a year will be fine.

Far to the south of Skipton, in the tropics and Caribbean, the fierce tropical heat and ultraviolet light means hyperlon/neoprene is probably essential as being the only sensible material choice for your tender.  

Conclusion on selecting your new Tender

We hope that all the above hints and tips, which we have gathered here from many years’ experience, will help you to select the best tender for your boat. There is a lot to think about, however if you follow the key points in the guidance above you will get the tender that matches your needs and desires.
Please remember the key issues for picking your perfect tender exactly the same, whether your main vessel is great or small.