#AskMark: Spool Uses Beyond DSMBs, Liveaboard Visa Rules & Regulators for Nitrox

@chrismacdonald2511

#AskMark: What else would you use the spool for other than deploying the DSMB?

A finger spool’s primary function is for attaching to buoys but, you can use them in a pinch if it’s all you have. There are many applications for a line in the water, mainly for ensuring a physical link to something such as your buddy in poor visibility, the exit of an overhead environment, or organising a search area.

A thicker rope can be hard to handle in the water and if you don’t need the strength of rope, then a thin line on a spool is easier to manage for a diver. If there’s something you want to find your way back to, then a finger spool is a handy tool to have on you. On the surface, I use my spool for all sorts of things from makeshift washing lines to helping with DIY projects. A strong nylon line can be useful for many things.

@KBrian-ek8wl

#AskMark: What are the visa requirements on a liveaboard since you’ll mostly be at sea?

You need the correct visa for the country you enter to board the liveaboard. For example, if you fly into Hurghada then you will need an Egyptian entry visa to enter Egypt to then travel to where you board the liveaboard. Liveaboards typically end where they start so, it’s unusual to require any additional visas.

The liveaboard organiser is the best to ask for advice on specific trips and requirements. You must be prepared for any additional entry fees or local requirements especially when you’re at sea. And while some visas you can pay for on arrival, others require applications, so do your research as early as possible.

@Racersbase

#AskMark: Is it correct that some regs are only good for air, not nitrox?

No. Most modern regulators are suitable for Enriched Air Nitrox up to 40% oxygen straight out of the box unless otherwise stated. For typical 30-32% nitrox, most regulators are perfectly fine to use. Double-check in the regulator’s user manual beforehand, there will be a section in there for use with nitrox. But I haven’t come across an ‘air only’ regulator yet.

Beyond 40%, your regulators require special O-rings and grease that don’t react with higher amounts of oxygen. Manufacturers often make dedicated nitrox versions of their regulators with green and yellow details for high oxygen mixes over 40%. In the EU, they will also have a different M26 fitting so that they only fit specific cylinders.